The Abbreviation ABS comes from the German Anti Blockier System.
A computer, sensors, and solenoid valves work together to sense wheel speed in order to modulate braking force if wheels lockup during braking.
ABS can help the driver retain control of the vehicle during heavy braking on slippery roads.
It works on the principle of braking a wheel until it just begins to skid (this is the point where braking efficiency would drop off dramatically) and then releasing the brake pressure and re-applying the brakes.
Wheel speed sensors identify the skid point and trigger a release in brake pressure.
The cycle is repeated many times a second.
The driver will feel a rapid pulsing at the brake pedal and hear a chattering noise as ABS is applied.
The use of a chemical or filter to remove unwanted particles or characteristics from something.
When light strikes a surface, some of it penetrates into the material and is trapped. This trapped energy is called absorption. Transformation into other forms suffered by radiant energy passing through a material substance.
A capacitor connected across a spark gap to reduce the discharge.
The volume of gas, measured at STP, dissolved by unit volume of a liquid under normal pressure (i.e., one atmosphere).
The fraction of the energy which is absorbed.
A measuring device which absorbs and dissipates power, e.g., the ordinary rope brake and the Froude hydraulic brake.
An instrument that measures the amount of moisture in the atmosphere
A refrigerator which creates low temperatures by using the cooling effect formed when a refrigerant is absorbed by chemical substance
ABS override button
A button or switch which disengages the automatic anti-lock braking system so that the driver can operate the brakes himself.
ABS relay valve
An electrically controlled valve which modulates the air pressure in the anti-lock braking system.
Abbreviation for Air Bypass Solenoid Valve (Mazda)
ABS warning light
Indicator lamp mounted in the instrument cluster. It illuminates when there is a problem in the anti-lock brake system. It will also illuminate momentarily when starting the vehicle to indicate that the lamp is functioning.
The action of two gear teeth making contact.
A part which stops the motion of another part from proceeding any farther.
The contact made between opposing teeth of two gears.
The structure that supports the end of a bridge.
The edge or side of a panel which joins the edge or side of another panel.
the cgs unit of potential difference in the electromagnetic system; the potential difference between two points when work of 1 erg must be done to transfer 1 abcoulomb of charge from one point to the other: equivalent to 10-8 volt (i.e., one hundred-millionth of a volt).
An abbreviation for across corners
An abbreviation for across corners
Indicates the distance on a nut or bolt head from one corner to the opposite corner rather than the distance from one flat surface (A/F) to the opposite.
The A/F measurement determines the size of wrench needed to install or remove the nut or bolt.
The A/C measurement determines the size of hole needed to insert a recessed nut or bolt head.
The transformation temperature on heating of the phase changes of iron or steel, subscripts indicating the designated change, e.g., Ac1 is the eutectoid (723°C) and Ac3 the ferrite/austenite phase boundary.
Abbreviation for Asphaltic concrete.
A mixture of asphalt cement, graded aggregate, mineral filler, and additives.
A vehicle brand built by the AC Cars Group, Limited of which the 1925-48 models are classic cars.
A vehicle brand built by the AC Cars Group, Limited of which the 1954-61 Ace models are milestone cars.
A vehicle brand built by the AC Cars Group, Limited
(AE) The action of increasing the fuel/air mixture during acceleration in order to improve the vehicle’s speed and its smooth response.
A small pump in a carburetor that squirts fuel into the carburetor throat as the throttle is opened. When you accelerate, the accelerator pump delivers extra fuel through the accelerator pump circuit to allow the engine to deliver more power. Also called accelerator pump.’
A part of a hydraulic system filled with nitrogen gas and used to store high pressure fluid to provide pressure assistance for system operation.
A pressurized container for an automatic leveling suspension system.
A part of the hydraulic system which is charged by the fluid pump, absorbs fluctuating fluid delivery, stores fluid at pressure, and can provide a rapid flow of fluid under pressure.
A device in the fuel line between the pump and filter that keep up the fuel pressure when the fuel pump is off thus preventing vapor lock and excessive fuel pump noise in having to build up pressure when needed
A vessel that stores hydraulic fluid under pressure.
A storage tank which receives liquid refrigerant from the evaporator and prevents it from flowing into the suction line before vaporizing.
A refrigerant storage device used on General Motors and Ford systems that receives vapor and liquid refrigerant from the evaporator.
The accumulator, which contains desiccant, performs a function similar to that of a receiver-drier it separates liquid from the vapor, retains the liquid and releases the vapor to the compressor.
A double-pivoting steering system where the outer ends of the steering arms are bent slightly inward so that when the vehicle is making a turn, the inside wheel will turn more sharply than the outer wheel.
This is done to compensate for the greater distance the outside wheel must travel.
Notice 20 degrees on left wheel and 30 degrees on right wheel
Arrangement whereby a line extended from the track-arms, when the wheels are set straight ahead, should meet on the chassis centerline at 2/3 of the wheelbase from the front, allowing the inner stub-axle to move through a greater angle than the outer.
The toe-out or toe-in of a vehicle with Ackermann steering when the wheels are positioned straight ahead.
In a vehicle with Ackermann steering (at the front of the vehicle), it is a non-rotating axle that is steerable and has two pivot points (one on each end of the axle) with vertical kingpins.
A charge for processing a vehicle lease and is probably not negotiable.
On a shorter term lease, the acquisition fee can have a large impact on the cost of the lease.
Abbreviation for Air Conditioning Relay
Abbreviation for Air Conditioning Refrigerant, Recovery, Recycling, Recharging
(A/C) The distance on a nut (for instance) from one corner to the opposite corner rather than the distance from one flat surface (A/F) to the opposite (which would be the size of wrench needed to install or remove the nut).
The purpose of the A/C dimension is to know how large a hole might be needed to insert a recessed nut.
(A/F) The distance on a nut (for instance) from one flat surface to the opposite flat surface, i.e., this is the size of the wrench needed to install or remove the nut.
Passive safety involves seat belts, airbags, bumpers, etc. so that in the event of an accident the passengers are protected.
Active safety involves factors which will assist the driver in avoiding an accident.
They include brakes, steering, handling response, acceleration, etc.
Energy from the sun collected and stored using mechanical pumps or fans to circulate heat-laden fluids or air between solar collectors and a building or vehicle.
While conventional suspension uses springs and shock absorbers to isolate the vehicle from the bouncing movement of the wheels when it contacts rough roads, active suspension uses power actuators which are controlled by a computer.
These actuators place the wheels of the vehicle in the best position to accommodate rough roads as well as compensate for different load levels.
A device which controls or operates another device.
A regulating valve which converts a form of energy into mechanical motion to open or close the valve seats
A device which responds to an output signal from a computer.
The portion of a regulating valve which converts mechanical fluid, thermal energy, or electrical energy into mechanical motion to open or close the valve seats
An electrical mechanism for moving or controlling something indirectly instead of by hand, such as a door lock. The output device that the PCM controls such as solenoids, relays, fuel injectors and stepper motors.
A control device which learns from repeated input so that under particular circumstances the control gives the learned response.
The ability of a control unit to adapt its closed-loop operation to changing operating conditions, such as engine wear, fuel quality or altitude, to maintain proper air-fuel mixture control, ignition timing or idle rpm. Also referred to as self-learning
A substance (like glue) that is used to join two substances.
An adhesive must bond both mating surfaces through specific adhesion (molecular attraction), through mechanical anchoring (by flowing into holes in porous surfaces), or through fusion (partial solution of both surfaces in the adhesive or its solvent vehicle).
Various descriptive adjectives are used with the term adhesive to indicate types, such as
a. physical form
Liquid adhesive, film adhesive, etc.
Resin adhesive, rubber adhesive, silicone based, mastic, etc.
Without changing the temperature of an enclosure or its surroundings, there is a change in the volume and pressure of the contents of the enclosure.
Compressing refrigerant gas without removing or adding heat.
The ratio of that work required to compress a gas adiabatically to the work actually done by the compressor piston or impeller.
An engine which is very efficient in transferring combustion heat to those parts of the engine which are being cooled by the flow of anti-freeze coolant — thus maintaining an even temperature of the engine.
In this way the engine is warm enough for efficient running and it does not overheat.
A change of state or process on a gas in which the gas neither receives nor rejects heat while it expands or is compresed.
The action of putting something into its proper alignment or position.
It may involve one component (e.g., He adjusted the gasket to fit properly.) or a series of components (e.g., He adjusted the poor idle — might mean he set the ignition timing, adjusted the carburetor screws, changed the choke setting, cleaned or replaced the spark plugs, etc.)
A measurement of electricity that includes the approximate amount of energy used to generate electricity. To approximate the adjusted amount of electricity, the site-value of the electricity is multiplied by a factor of 3. This conversion factor of 3 is a rough approximation of the Btu value of raw fuels used to generate electricity in a steam-generation power plant.
A device for moving something into the correct position or into a different position — usually a better position.
A tool used to determine the small distance between two parts so that they can be brought within specifications.
A small screw usually found on carburetors, brakes, or headlights which change the way something operates, such as increasing or decreasing the amount of fuel entering the engine; or changing the idle speed; or tightening up the brakes; or changing the setting on rocker arms; or the level of the headlights.
A thin washer or plate which reduces or increases the clearance between two components (depending upon where they are placed). While some valves are adjusted by screws on the rocker arm, others are set by inserting a shim to make the same adjustment.
A small threaded cylinder on the end of the tie rod which shortens or lengthens the rod to make changes in the toe-in and toe-out.
British spelling for airfoil a body or body panel shaped like a wing so as to produce an aerodynamic reaction (lift) normal to its direction of motion, for a small resistance (drag), in that plane; e.g., a wing, plane, aileron, tailplane, rudder, or elevator.
Abbreviation for across flats which is the distance on a nut (for instance) from one flat surface to the opposite flat surface, i.e., this is the size of the wrench needed to install or remove the nut.
(ABDC) The position of the piston as it starts its way up.
A device for burning excess carbon wastes produced by the engine so that Air pollution is reduced.
In an internal-combustion engine, persistence of the combustion process beyond the period proper to the working cycle, i.e., into the expansion period.
Delayed further collapse of underground workings after a rockburst.
A device in a diesel engine which removes the relatively warm air which enters the engine.
Chamber in which heat generated during compression of air is removed, allowing cool air to be piped underground.
Cooling the engine intake air after the turbocharger and prior to introduction into the cylinder. Aftercooling increases engine power and lowers NOx emissions. Also called Intercooling
The period during which the glow plugs of a diesel engine continue to operate after the engine is started.
The glow of a gaseous medium immediately after the cessation of electric current or downstream of an electric discharge.
All products and services used in the repair and maintenance of vehicles after the vehicle has been sold.
Aftermarket converted vehicle
A standard conventionally fueled, factory-produced vehicle to which equipment has been added that enables the vehicle to operate on alternative fuel.
Accessories and replacement parts added to a vehicle after it has been sold.
An overdrive device which is not original equipment, but has been added after it has been sold.
Goods not for use as original equipment in the production of light-duty vehicles or heavy-duty vehicles, i.e., products and services used in the repair and maintenance of these vehicles.
Although most vehicles come from the manufacturer with some rustproofing, there is no guarantee that every part of the exposed chassis and frame will be protected from the elements and the possibility of rust. Therefore rustproofing is applied by the owner of the vehicle to reduce the possibility of rust. If this rustproofing is not done when the vehicle is new, it might seal in the rust and create a greater problem.
Aftermarket vehicle converter
An organization or individual that modifies OEM vehicles after first use or sale to operate on a different fuel (or fuels).
Nearest the back of the ship
The compartment in the narrow part of the stern, aft of the last water-tight bulkhead.
A vertical straight line at, or near the after edge of rudder post.
(ASE) When an engine is first started, it needs a little richer fuel-air mixture (i.e., more fuel, less air). In a carbureted engine, this is accomplished by the choke (which restricts the amount of air). In a fuel injected engine, the after-start enrichment device increases the amount of fuel. As the engine warms up, the device gradually reduces the amount of enrichment. Some devices just reduce the amount gradually over time without sensing the temperature of the engine.
Devices which remove pollutants from exhaust gases after the gas leaves combustion chamber (e.g., Catalytic converters or Diesel particulate filters). The term exhaust gas aftertreatment is considered derogatory by some in the emission control industry, but there is no consensus on the use of such alternatives as post-combustion treatment or exhaust emission control
Although you can register your vehicle and obtain your license from a government office, some states and provinces permit an agent to perform that same service and allow the agent to collect an extra fee for the service. In this way the lineup at the government office is reduced.
Rock of specified quality and gradation.
Materials such as sand or chipped rock that are spread on paved roads to increase vehicle traction. Also called abrasives
A French expression to indicate the reinforced front, rear, and side safety structures of a vehicle. If the strengthened structure causes more than normal damage to another vehicle, a pedestrian, or the occupants of the vehicle, then that structure is aggressive.
A driving style in which the driver exceeds the speed limit, tailgates, weaves through traffic, fails to signal lane changes, fails to obey traffic signs and signals. May lead to or cause road rage.
The cracking, checking, or general deterioration produced by exposure of an adhesive, coating or sealer to the weather or some other given set of conditions for a length of time
The deterioration of rubber properties by oxidation over a period of time.
A change in the properties of some metals after heat treatment or cold working (i.e., hammering or bending when metal is cold).
The final stage of precipitation hardening, producing an increase in strength and hardness in metal alloys, due to precipitation of second phase particles from supersaturated solid solution over a period of days at room temperature, or several hours at an elevated temperature (called Artificial aging)
Loss of strength in the cladding or the pressure vessel in a nuclear reactor due to irradiation. Artificial aging would be the simulation of such processes by increasing the rate of irradiation to obtain information more rapidly
Change in the properties of a substance with time. A change in the magnetic properties of iron, e.g., increase of hysteresis loss of sheet-steel laminations; also the process whereby the subpermanent magnetism can be removed in the manufacture of permanent magnets
A type of spray gun paint container which has an agitator.
A device used to cause motion in confined fluid
A device for mixing paint by shaking the container.
A tank, usually cylindrical, which has a mixing device such as a propeller or airlift pump near the bottom. Finely ground mineral slurries (the aqueous component perhaps being a leaching solution) are exposed to appropriate chemicals for purpose of extraction of gold, uranium, or other valuable constituents. Types include pachuca tank or Brown agitator.
A bicycling or motorcycling term describing the space or gap between the tires and the ground when the bike takes a jump. Both tires must be off the ground before it can be called ‘air’ as in the expression, ‘I really caught air on that last jump.’
A gas containing approximately 80% nitrogen, 20% oxygen, and a small portion of other gases and water vapor. One of the essential factors in a combustion engine (fuel, air, proper proportion of mixture, compression, timing, and spark).
A gas for combustion, heating, cooling, ventilation, breathing, and other uses.
An Abbreviation for Air Injection Reactor system of reducing objectionable exhaust emissions. A belt-driven pump sends air through a pipe to the exhaust manifold and/or catalytic converter to help control emissions. Replacement for the term EAC
(AAS) A passive air injection system that uses a one-way valve instead of an air pump to introduce extra air into the exhaust stream.
Air aspirator valve
A device that uses a diaphragm to draw air into the exhaust system to reduce emission. If a large volume of air is needed, an air pump is used instead
Air-assisted hydraulic brake system
A hydraulic-type brake system actuated by an air hydraulic power unit.
Abbreviation for Air Bypass Solenoid
A device which is part of the passive safety system. In the event of a collision, sensors will cause the air bag to be deployed so that your head will be pillowed by the bag instead of hitting the instrument panel or windshield.
A durable, inflatable bag used to force and secure freight to the inside walls of a trailer.
A device which is part of the passive safety system. In the event of a collision, Sensors will cause the airbag to be deployed so that your head will be pillowed by the bag instead of hitting the dash or windshield.
All the components that make up the airbag system Airbag, inflator, cover, and sensor. Also called airbag unit.
Airbag restraint system
A system which uses an airbag to restrain occupants in the event of a collision. They may be placed on the instrument panel or doors or even in the shoulder strap. Also called passive restraint system.
A plastic, fiberglass, or metal container which may hold the air filter. Some are mounted between the carburetor and the air filter. This box provides a volume of still, filtered air for induction into the engine.
A system of braking which is usually found on large truck in which compressed air pushes against a brake piston or diaphragm in order to apply the brakes to stop or slow the vehicle.
An extendable device, most commonly a hinged flap on wing or fuselage, controlled by the pilot, to increase the drag of an aircraft. Originally a means of slowing bombers to enable them to dive more steeply, it is an essential flight control on clean jet aircraft and sailplanes
A mechanical brake operated by air-pressure acting on a piston
An absorption dynamometer in which the power is dissipated through the rotation of a fan or propeller.
An inverted opening placed in the chimney of a gas furnace to prevent back pressure from outside wind from reaching the furnace flame or pilot
A paint spray gun used for precise detailing work and custom painting.
(ABPV or ABV) a backfire-suppressor valve used in air injection systems. During high engine vacuum conditions such as deceleration, it vents pressurized air from the air pump to the atmosphere in order to prevent backfiring. At other times, it sends air to the exhaust manifold. On vehicles with a three-way catalyst, it sends air to the oxidation catalyst only when the engine warms up. Also called an anti-backfire valve, diverter valve, or gulp valve.
A small auxiliary combustion chamber used in certain types of compression-ignition engines, for promoting turbulence and improving combustion.
A space provided in the piston or cylinder to trap air during the compression stroke. It later flows out into the combustion chamber
Air charge temperature
(ACT) The temperature of the air being forced into the carburetor or fuel injection system. An ACT sensor measures this temperature.
Air charge temperature sensor
(ACTS) a thermistor sensor that inputs the temperature of the incoming air stream in the air filter or intake manifold to the computer. It can be located in the intake manifold (EFI systems) or the air cleaner. On carbureted vehicles, if the air is cold, it signals the choke to let off slowly. It then alters engine speed after the choke is off and below a certain temperature, dumps air from the air injection system to the atmosphere for catalyst protection.
A device which filters the air entering the engine to remove airborne impurities, dust, dirt, and bumblebees. Without it, impurities could cause internal wear and damage. Also called air cleaner.
A device using filters or electrostatic precipitators to remove indoor-air pollutants such as tobacco smoke, dust, and pollen. Most portable units are 40 watts when operated on low speed and 100 watts on high speed.
(ACL BI-MET) a component of a thermostatic air cleaner system. It senses the temperature of incoming fresh air and bleeds off vacuum when the air is warm. When the air is cold, the sensor directs vacuum to the air cleaner vacuum motor.
Air cleaner duct and valve vacuum motor
(ACL DV) a component of thermostatic air cleaner systems. It opens and closes the air duct valve to provide heated or unheated air to the engine in accordance with the temperature of the incoming air.
Air cleaner element
Air filter element
The replaceable filter which prevents impurities from the air which enters the combustion chamber. Also called air filter element.
Air cleaner horn
Many air cleaner canisters have a spout or horn extending from the edge of the canister into which the air is taken in.
The neck, called a snorkel, into which air flows en route to the throttle body
Coil on some types of heat pumps used either as an evaporator or a condenser.
A medium-temperature collector used predominantly in space heating, using pumped air as the heat-transfer medium.
A device which compresses air and stores the air into a tank so that the compressed air can be used in a shop to fill tires, run tools, spray paint, etc. In a vehicle, it can be used in brake systems, leveling systems, automatic tire inflation systems, and air supply systems.
The state of exchanging warm air for cold so that a vehicle or home is cooler than the outside temperature.
(A/C) or (Air)
A device used to control temperature, humidity, cleanliness, and movement and sometimes the air purity, in an enclosed space
A system of devices which causes a reduction or control of the temperature and humidity within the cab of a vehicle. It was first offered on the 1941 Packard. Two types are used in vehicles: receiver-dryer type and accumulator type.
(ACCC signal) the input to the computer regarding the status of the air conditioner clutch (engaged or disengaged).
A system or process for controlling the temperature, humidity, air movement, and sometimes the purity of the air in an enclosed space by use of a refrigeration unit powered by electricity or natural gas. Note Fans, blowers, and evaporative cooling systems (swamp coolers) that are not connected to a refrigeration unit are excluded..
(ACV) a vacuum-controlled diverter valve (or a combination bypass/diverter valve) in an air injection system that diverts air pump air to either the upstream (exhaust manifold) or downstream (oxidation catalyst) air injection points as necessary.
Any device whose produced heat is reduced by the flow of air around it
An electric apparatus in the heat caused by the losses is removed solely by natural or fan-assisted air flow.
A heat exchanger which transfers the heat of compression from condensing coils to surrounding air. This may be done either by convection or by a fan or blower.
Air cooled engine
Air cooled engine
An engine which generally has large fins or ribs and is often exposed to the outside air. The heat of the engine is dissipated through the fins of the engine. In contrast, the heat in a liquid-cooled engine is reduced by channels throughout the inside of the engine through which liquid (antifreeze) passes. Most older Volkswagens and some motorcycles use air cooled engines.
An attachment called a spoiler which is usually located below the front bumper. Its design, shape, and placement helps to reduce the flow of air under the vehicle. It may help to increase the flow of air to the radiator and engine compartment, affect aerodynamic drag, or affect positive and negative lift.
A barrier beneath the front bumper used to divert the flow of air beneath the car. Usually intended to reduce lift and drag.
A panel which is positioned at an angle on the roof of a truck or on the front of the hood to cause the air to flow over the vehicle. The hood air deflector (often made of transparent plastic) is designed to prevent bugs from hitting the windshield. British term is ‘air shield.’
Air distribution outlet or grille designed to direct airflow into desired patterns.
Resistance to the motion of a body passing through the Earth’s atmosphere, most serious in the lower regions, producing changes in the geometry of the orbit, even causing the body to re-enter. More generally the term atmospheric drag is used in reference to other planets.
Allowing paint to dry at ambient (surrounding) temperatures, without the aid of an external heat source.
Allowing paint to dry at ambient (surrounding) temperatures, without the aid of an external heat source.
Air drying adhesives
Adhesives that can be dried at room temperature without the use of heat. This type of adhesive consists of solid particles dissolved or dispersed in a liquid. When the liquid evaporates, it leaves the dry adhesive film. Most elastomer based adhesives are of this type.
A tube or channel which permits heated and ventilated air to enter the passenger compartment, building, or machinery to provide heating, cooling, or ventilation.
Said of an oil plunger pump which no longer sucks because gas or air has filled the suction chamber.
A type of air pump used for maintaining a partial vacuum in a vessel through the agency of a high-velocity steam jet which entrains the air and exhausts it against atmospheric pressure.
An engine in which air is used as the working substance. Rapid heating from an external source expands the air in the cylinder with consequent motion being imparted to a piston. After transfer to a compression cylinder, for rapid cooling, the air is returned to the working cylinder for the next cycle. Also called hot-air engine.
A small reciprocating engine driven by compressed air.
(AFC) a Bosch term for its early pulse fuel injection systems; usually refers particularly to the system which uses an L-Jetronic air mass sensor.
Air flow meter
A sensor which measures the rate at which air enters the engine. In Bosch systems, any device that measures the amount of air being used by the engine. The control unit uses this information to determine the load on the engine. The two most common examples of airflow meters are the air-flow sensor used in the Bosch L-Jetronic and the air mass sensor used in the Bosch LH-Jetronic systems.
An instrument, mainly experimental, for measuring the airflow in ducts
A device in an electronically controlled fuel injection system which detects the amount of air entering the combustion chambers. Continuous injection systems use an airflow sensor plate to measure airflow volume; electronic systems use a vane or flap-type airflow sensor.
A detection device that provides information on the volume flow or mass flow rate of the intake air to the engine.
An aerodynamic device used to improve traction by increasing the downward force on either end of the car. It can be compared to an airplane wing with this primary difference A wing is designed to provide lift so it can fly; the air foil pushes the vehicle closer to the ground. Although they may be called ‘wings,’ they are properly air foils. They increase the cornering ability, improve Stability, but add aerodynamic drag.
The cross-sectional shape or profile of an airfoil.
Air Freight Container
A smaller and lighter cargo container often made out of fiberglass designed to hold cargos that are shipped in airplanes.
(A/F ratio) The mass of air supplied to the engine divided by the mass of fuel supplied in the same period of time (i.e., ratio of air weight to fuel weight). The Stoichiometric, or chemically correct, air-fuel ratio is the exact ratio necessary to burn all the carbon and Hydrogen in the fuel to carbon dioxide and water with no Oxygen remaining. The Fuel-air ratio is the reciprocal of the air-fuel ratio. The amount of air is much greater than the amount of fuel, usually between 14.7:1 and 15:1, depending on the type of fuel system.
Gap with points or knobs, adjusted to breakdown at a specified voltage and hence limit voltages to this value.
Section of air, usually short, in a magnetic circuit, esp. in a motor or generator, a relay, or a choke. The main flux passes through the gap, with leakage outside depending on dimensions and permeability.
Air gap voltage
Voltage across a gap or equivalent filler of nonmagnetic material across the core of a choke, transformer, or other magnetic device.
(AG) An American Motors air injection system that uses an air pump to supply air into the exhaust manifold to reduce HC and CO emissions.
Air gulp system
A system in vehicles with secondary air injection or induction, which prevents an very rich mixture of air-fuel from entering the inlet manifold during deceleration. If it did enter, unburned fuel would be forced over the hot exhaust system causing backfiring (i.e., uncontrolled detonation). The air gulp system prevents this condition by allowing a quantity of air to combine with the rich mixture in the inlet manifold.
Air gulp valve
A diverter valve which adds an amount of air to the rich air-fuel mixture entering the intake manifold during deceleration.
A hammer-tool that is powered by compressed air and used for riveting, or chipping. Sometimes called an air gun or gun.
Fan-blower, heat transfer coil, filter, and housing parts of a system.
A term for older, air-cooled BMW Boxer Twin motorcycles.
Air hold fitting
A tool which uses air pressure to keep the valves closed when working on an OHV engine. The device is screwed into the spark plug holes and air pressure keeps the valves from dropping down. In this way the valve seal or valve spring can be replaced without removing the cylinder head.
It is also a term used for a warning horn which is operated by forcing compressed air through a reed.
Air horn baffle
Used on some Rochester Quadrajet carburetors to prevent incoming air from forcing fuel into the secondary wells through the bleed tubes. Prevents secondary-nozzle lag during heavy acceleration.
Air hydraulic brake power-assist unit
A unit consisting of an air cylinder or chamber, hydraulic cylinder(s) and control valve in which driver effort is combined with force from the cylinder piston or chamber diaphragm to displace fluid under pressure for actuation of the brake(s).
An air brake system that uses a single air chamber to power a hydraulic master cylinder that applies the wheel friction assemblies through conventional brake calipers and wheel cylinders.
A paint spraying process where the coating material (i.e., paint) is not atomized by a stream of air. Instead, it is subjected to high pressure and forced through a narrow jet or nozzle which causes it to be atomized.
An air-powered axle which, when lowered, will both convert a vehicle into a multi-axle unit and provide greater load carrying capacity
A pipe, hose, or duct in a vehicle which permits the flow of air or vacuum.
The supply line coming from an air compression tank to drive air tools or inflate tires.
Straight line drawn on the magnetization curve of a motor, or other electrical apparatus, expressing the magnetizing force necessary to maintain the magnetic flux across an air-gap in the magnetic circuit.
A type of gas refrigerating machine based on the Sterling or hot-air engine cycle.
A bubble of air trapped in a fluid circuit which interferes with normal circulation of the fluid.
Device by which access is obtained to the working chamber (filled with compressed air to prevent entry of water) at the base of a hollow caisson. The worker at surface enters and is shut in an air-tight chamber filled with air at atmospheric pressure. Pressure within this air-lock is gradually raised to that used in the working chamber, so that the worker can pass out through another door and communicate with the working chamber.
Air management system
(AMS) used to control the injected air to the exhaust manifold and catalytic converter. This improves the pollutant conversion efficiency in the converter.
Air management unit
(AMU) — An assembly of pressure switches, and other valves located in a chassis cross-member, designed to control the pneumatic accessory functions of a vehicle using the multiplex electrical system.
Air mass flow
In a gas turbine power plant, the quantity of air which is ingested by the compressor, normally expressed in pounds or kilograms per second.
Air mass meter
An instrument which measures both engine intake air mass and factors which affect air density, such as temperature, humidity, and pressure.
Air mass sensor
An airflow detection device that uses the changing resistance of a heated wire in the intake airstream to measure the mass of the air being drawn into the engine. Also referred to as a hot-wire sensor.
An apparatus used to measure the rate of flow of air or gas.
A control in a paint spray gun which adjusts the amount of air.
The vent or opening where the passage of air exits — especially in systems for air conditioning, ventilation, and defrosting as air enters the passenger compartment or flows out of the compartment.
Air outlet valve
A vacuum operated door which directs air flow into the heater core or ducts, usually located in or near the plenum blower assembly. A vacuum operated door which directs air flow into the heater core or ducts, usually located in or near the plenum blower assembly.
(AO) An electric motor intended for Fan and Blower service and cooled by the air stream from the fan or blower
Any device used for transferring air from one place to another. A compressor increases the pressure, a Vacuum pump reduces the pressure and a blower causes a rapidly moving air blast
A device used in the emissions system to provide fresh air into a vehicle’s exhaust to help complete the combustion process and reduce emissions. To get accurate lambda measurements with the LM-1, air pumps should be temporarily disabled.
The extent to which air is free from contaminants, conventionally taken to be the respiratory irritants nitrogen dioxide and sulfur dioxide.
Air Quality Management District
(AQMD) A term used principally in California to describe administrative districts organized to control air pollution. Nationwide, AQMDs are parallel to the areas designated for classification against the National Ambient Air Quality Standards (NAAQS). Generally, AQMDs and their national parallel encompass multiple jurisdictions and closely follow the definition of Consolidated Metropolitan Statistical Areas and Metropolitan Statistical Areas.
A Ratchet tool powered by air pressure from an air compressor
The ratio of actual intake air volume to the air volume theoretically needed for complete combustion of a particular amount of the fuel. This ratio is represented by the Greek letter lambda λ (which looks like the letter y upside-down).
The resistance of the air to forward movement, sometimes called aerodynamic drag. This is a factor of the shape of the vehicle, the objects which stick out (i.e., mirrors, mufflers, bumpers), the amount of turbulence at the rear of the vehicle, the nature of the vehicle’s skin surface, and the amount of air going through the vehicle for cooling and ventilation. The faster you go, the greater the air friction (air friction = velocity x velocity). The faster you go, the greater the amount of power needed to overcome this Drag (power = velocity x velocity x velocity).
(ARS) A suspension system in which the load is supported on air-filled rubber bags rather than steel springs. The engine’s air compressor fills the reservoir tanks which supplies air for the suspension and the air brake system.
Any type of screw designed to rotate in air; defined in 1951. Term now obsolete and replaced by Propeller, a device for propelling aircraft, and Fan, a rotating bladed device for moving air in ducts or wind tunnels.
A valve in a two-stage catalytic converter with secondary air injection. It is operated by a solenoid and is triggered by the electronic control module. It directs air to the exhaust valve ports or to the midbed catalytic converter, depending on operating conditions.
The unit in which sensing element is located in refrigerated space.
A detection device which checks for the presence of air pollutants entering the passenger compartment. If the pollutant concentration is too high, it operates flaps to cut off the external air to the air conditioning system.
An air cone with a floating plate which measures air flow and determines plunger position on K-Jetronic type systems
A type of power booster that contains atmospheric pressure in both chambers of the booster when the brake pedal is at res. When the pedal is applied, the front chamber is opened to manifold vacuum, causing the diaphragm of the booster to move toward the master cylinder which assist the driver in the application of the brakes.
A Suspension system using air rather than metal springs to support the vehicle and control ride motions. Air springing results in a smoother ride, because the natural frequency of vibration of an air spring does not vary with loading as it does with metal springs. Air springs can be made very soft for the lightly loaded condition and the pressure automatically increased to match any increase in load, thus maintaining a constant sprint vibration period any load.
Air suspension power booster
A type of power booster that contains atmospheric pressure in both chambers of the booster when the brake pedal is at rest. When the pedal is applied, the front chamber is opened to manifold vacuum causing the diaphragm of the booster to move toward the master cylinder which assists the driver in the application of the brakes.
A heat exchanger used on a turbocharged engine, which uses liquid coolant from the rad to cool the air coming from the turbo into the intake manifold.
A tool such as an impact driver or drill which is powered not by electricity, but by air pressure coming from an air compressor.
Toxic air pollutants defined under Title II of the CAA, including benzene, formaldehyde, acetaldehyde, 1-3 butadiene and polycyclic organic matter (POM). Benzene is a constituent of motor vehicle exhaust, evaporative and refueling emissions. The other compounds are exhaust pollutants.
A device which is placed between the compressor and a paint spray gun to provide clean spraying air and to regulate the oil pressure.
A valve in a spray gun which controls the flow of air by the operation of the trigger.
A type in which a spring-closed or weight-closed air valve opens in response to engine demand. This valve, through suitable linkage, varies the fuel-orifice opening to secure the desired mixture ratio throughout the range of operation. SU and Stromberg CD carburetors operate on this principle, referred to also as Constant-vacuum, Constant-depression, or variable-Venturi.
A valve, either manual or automatic, used to remove air from the highest point of a coil or piping assembly
Abbreviation for Air Inlet Temperature sensor–Used to measures inlet air temperature for fueling
Abbreviation for atmospheric/automatic inlet valve, a system used on early motorcycle engines in which the intake valve is held shut by a weak spring and opens by atmospheric pressure when the falling piston creates a vacuum in the cylinder.
Abbreviation for air injection valve
Abbreviation for Anti-knock Index — the average of the RON and MON. This is the number posted on the retail gasoline pumps normally indicating 87, 89, or 92 octane. Racing gasoline have AKI’s from 100 to 118.
Abbreviation for As Low As Reasonably Achievable. Used of radiation levels or decontamination.
A warning sound made by a security or safety device to warn off thieves, alert the driver to take some preventative measures (e.g., secure the seat belts), or warn those around the vehicle (e.g., backup warning alarm). Alarms may sound as a buzzer, a chime, or a human voice.
A theft protection system which may do one or more of the following Sound the horn or an auxiliary siren, flash the lights, lock the hood and trunk, make the ignition inoperative, put the engine in a Limp-home mode, notify the police, and alert the vehicle owner.
The condition of a vehicle which is protected by an alarm system.
Abbreviation for Assembly Line Communications Link (GM)
A general term for compounds formed from hydroxyl groups attached to carbon atoms in place of hydrogen atoms. The series of molecules vary in chain length and are composed of a hydrocarbon plus a hydroxyl group; CH(3)-(CH(2))n-OH (e.g., methanol, ethanol, and tertiary butyl alcohol). It may be used as a fuel.
A beverage which impairs a driver’s skill in operating a vehicle safely. Although the law has set down limits of the amount of alcohol allowable in the bloodstream before a person is considered drunk, the effects of the slightest amount of alcohol can impair one’s driving skill.
Water and alcohol solution which remains a liquid below 0°C
A machining operation which corrects an engine’s out-of-round and warped main bearing housings with a special honing mandrel. It must be done with stationary equipment.
Devices used in mounting floating drums on the arbor of a brake drum lathe.
A tool shaped like a thin rod used to make sure holes line up when assembling two or more components. Especially used on items which may move to one side before the other side can be aligned or another component installed or when the gasket is likely to slip out of place.
A storage battery which uses an alkaline electrolyte (dilute potassium hydroxide).
A process of removing an oily or greasy substance with the use of an alkaline solution. Often used in preparing a surface for painting.
Alkaline fuel cell
(AFC) A type of hydrogen/oxygen fuel cell in which the electrolyte is concentrated KOH (varies between 35 to 85 percent by weight depending on the intended operating temperature) and hydroxide ions (OH-) are transported from the cathode to the anode. Temperature of operation can vary from below 120°C to approximately 250°C depending upon electrolyte concentration.
The product of an alkylation reaction. It usually refers to the high-octane product from alkylation units. This alkylate is used in blending high octane gasoline.
A refining process for chemically combining isobutane with olefin hydrocarbons (e.g., propylene, butylene) through the control of temperature and pressure in the presence of an acid catalyst, usually sulfuric acid or hydrofluoric acid. The product, alkylate, an isoparaffin, has high octane value and is blended with motor and aviation gasoline to improve the antiknock value of the fuel.
An engine which uses a light alloy for the block, crankcase, sump, and cylinder head.
Once popular slide-valve design with an internal passage designed to reduce valve travel and wear.
A vehicle brand of which the 1946-56 Series J2, K2, K3 models are milestone cars.
The fixed charge to transport a number of items in a single vehicle at one time from the consignor (i.e., shipper) to the consignee (i.e., receiver). This rate is based on the actual cost of transportation not the value of service.
A fastening device (either a wood screw type or bolt threads) with a recessed hexagon hole in the head. Also called a hex hole screw.
A modern passenger car body style in which the fenders, headlamps, and radiator grille are one smooth body line. It contrasts with the style before World War II where the fenders and headlights were separate from the main body.
An rod with six sides and often L-shaped. Used to remove certain bolts or screws and fastenings, especially set screws. Sometimes called hex wrenches or Allen key.
A privately maintained thoroughfare, tract, or easement, usually narrower than a street, which provides access to the rear boundary of one or more lots and is not intended for general traffic circulation.
A public road, usually single lane, which separates rows of houses and is used for access for garbage pickup, etc.
A groove in a block of metal along which ball bearings or a rod slides.
A colloquial term for a large piece of a tire on the road.
A small spring clip which is X-shaped. As you squeeze the two legs of the clip, the other two jaws (usually serrated) open. Used to make temporary electrical connections. Larger ones are used at the ends of jumper cables. The British call it a crocodile clip.
The engine bay hood that opens from the front and its hinge is near the firewall. Although it is the most common, older cars opened from the side. Some sports cars and large trucks open with the hinge at the front of the vehicle.
A mountain bicycle designed to balance climbing and descending abilities with slightly more emphasis on descending prowess; features dual suspension with 4 to 6 inches of travel
A warehouse term for product which has been ordered for a specific customer or promotional event and is not to be used for other requests. A good WMS will tag the items so that they are not available apart from the designated purpose.
A situation where the driver uses the maximum braking effort possible. Although this seems to be the best way to stop a vehicle, in fact it may not because there may be the tendency to swerve or the brakes may overheat and lose effectiveness. It is better to pump the brakes (if ABS is not available) to control steering and get maximum braking.
Allowable working pressure
The maximum gauge pressure at which a part or system may be operated in accordance with the provisions of this standard. It is the pressure used in determining the setting of pressure limiting or relieving devices installed to protect the part or system from accidental overpressuring.
A reduction of the shipping costs if the carrier does not provide the necessary equipment (e.g., pallet jack, crane) and that equipment is supplied instead by the shipper.
Cast-iron containing alloying elements in addition to carbon and the normal low levels of manganese and silicon, usually some combination of nickel, chromium, copper, and molybdenum. These elements may be added to increase the strength of ordinary irons, to facilitate heat treatment, or to obtain martensitic, austenitic, or ferritic irons.
A generic term used to describe any non-steel road wheel usually cast as one piece. The usual alloys are either aluminum or magnesium; the latter material led to the common usage of the term mag wheel, often referring to any non-steel wheel or even a one-piece plastic wheel. Also called Cast Aluminum Wheel
A tire which has a number of lugs or knobs used to propel the vehicle over rough surfaces.
All terrain vehicle
A vehicle used in rough surface conditions. Also called off-road vehicle.
A model of automobile from the Buick division of General Motors from 2005-current. The same model in the United States is called the LaCrosse (an offensive term in Quebec). It has a 3.8 litre V-6 engine and a 4-speed automatic transmission; wheelbase is 2807mm; overall length is 5031mm.
A self-paced long-distance bicycle ride as promoted by the Audax Club Parisien, the Randonneurs Mondiaux, and the Randonneurs USA. You can ride at your own pace so long as you finish within the time limit. This is not a race where riders are recognized for finishing ahead of other riders. The important thing is to finish the ride.
An early car term referring to the first convertibles. Commonly used in the twenties and thirties to denote a four door convertible sedan.
A tire that can be used on roads that are bare or covered with rain, snow, or ice.
(AWD) A variation of four-wheel drive (4WD) designed to improve on-road traction in unfavorable road conditions or for ultra high performance driving. All-Wheel Drive (AWD) reduces wheel slippage and provides greater driver control over the vehicle. AWD usually does not require the driver to actively engage the system and does not have a low range. AWD automatically splits engine torque between the front and rear wheels as needed. All-Wheel Drive is generally an on-road system and is not designed for off-road use.
(AC) An electric current that first flows one way in the circuit and then the other at regularly recurring intervals. This is the type used in homes. It contrasts with direct current. It is also the type of current produced by a vehicle’s alternator. Since the rest of the vehicle uses direct current, the current coming from the alternator must be changed by the rectifier.
Current in which the charge-flow periodically reverses, as opposed to direct current, and whose average value is zero. Alternating current usually implies a sinusoidal variation of current and voltage.
As defined pursuant to the EPACT, methanol, denatured ethanol and other alcohols, separately or in mixtures of 85% by volume or more with gasoline or other fuels, CNG, LNG, LPG, hydrogen, coal derived liquid fuels, fuels ‘other than alcohols’ derived from biological materials, electricity, neat biodiesel, or any other fuel determined to be substantially not petroleum and yielding ‘substantial energy security benefits and substantial environmental benefits.’
Low-polluting fuels which are used to propel a vehicle instead of high-sulfur diesel or gasoline. Examples include methanol, ethanol, propane or compressed natural gas, liquid natural gas, low-sulfur or ‘clean’ diesel and electricity.
Alternative Fueled Vehicle
(AFV) Abbreviation for Alternative Fueled Vehicle — a vehicle powered by a fuel other than gasoline or diesel.
A fuel provider (or any affiliate or business unit under its control) is an alternative-fuel provider if its principal business is producing, storing, refining, processing, transporting, distributing, importing, or selling (at wholesale or retail) any alternative fuel (other than electricity); or generating, transmitting, importing, or selling (at wholesale and retail) electricity; or if that fuel provider produces, imports, or produces and imports (in combination), an average of 50,000 barrels per day of petroleum and 30% (a substantial portion) or more of its gross annual revenues are derived from producing alternative fuels.
Alternative Fuels Data Center
(AFDC) A program sponsored by DOE to collect emissions, operational and maintenance data on all types of AFVs across the country.
Alternative Fuels Utilization Program
(AFUP) A program managed by DOE with the goals of improving national energy security by displacing imported oil, improving air quality by development and widespread use of alternative fuels for transportation and increasing the production of AFVs.
As defined by the Energy Policy Act, any dedicated, flexible-fueled, or dual-fueled vehicle designed to operate on at least one alternative fuel.
A vehicle designed to operate on an alternative fuel (e.g., compressed natural gas, methane blend, electricity). The vehicle could be either a dedicated vehicle designed to operate exclusively on alternative fuel or a nondedicated vehicle designed to operate on alternative fuel and/or a traditional fuel.
Alternative fuel vehicle converter
An organization (including companies, government agencies and utilities), or individual that performs conversions involving alternative fuel vehicles. An AFV converter can convert (1) conventionally fueled vehicles to AFVs, (2) AFVs to conventionally fueled vehicles, or (3) AFVs to use another alternative fuel.
Alternative Motor Fuels Act of 1988
(AMFA) Public Law 100-494. Encourages the development, production and demonstration of alternative motor fuels and AFVs.
alternative power plant
Hybrids, fuel cells, and other innovations designed to replace the internal combustion engine.
(ALT) A device which produces AC by converting the engine’s turning (mechanical) energy into alternating electrical current at all engine speeds. The AC must be rectified (converted from AC to DC) by using diodes before reaching the vehicle’s electrical system. The alternator is driven by a belt at the front of the engine. Alternators replaced the direct-current (DC) generators used up to the 1960’s because they were less efficient especially at idle. The electrically demanding options like air conditioning forced the use of alternators over generators.
A model of automobile manufactured by Nissan in Japan
An instrument to reveal the height (or barometric pressure) above sea level.
An aneroid barometer used for measuring altitude by the decrease in atmospheric pressure with height. The dial of the instrument is graduated to read the altitude directly in feet or metres, the zero being set to ground or aerodrome level.
The height in feet or metres above sea level. For precision in determining the performance of an aircraft, this must be corrected for the deviation of the meteorological conditions from that of the International Standard Atmosphere.
The angular distance of a heavenly body measured on that great circle which passes, perpendicular to the plane of the horizon, through the body and through the zenith. It is measured positively from the horizon to the zenith, from 0° to 90°.
The line through the vertex of a geometrical figure or solid perpendicular to its base.
(Al or Alum) A silver-white metal which is used in cars because of its lightness. In pure form, it does not have the strength of the same size of iron. Thus vehicle manufacturers use aluminum in an alloy form to produce body panels, wheels, engine blocks, transmission housings, differential housings, and even frames. British spelling adds an extra i near the end of the word aluminium and pronounces it al-you-MIN-ee-um instead of ah-LOO-min-um.
Abbreviation for ‘air mass’ or ‘atmospheric mass’ which is the measure of the absorption and scattering of light by the Earth’s atmosphere. AM 0 indicates no atmosphere in the path of the light. This is the condition in space where the power density of light is about 1.36 kilowatt/square metre. AM 1 is the condition at the surface of the Earth where the light passes through one atmosphere. Power density is about 1.0 kilowatt/square metre.
(ASTM) Society for developing and publishing agreed standards. A non-profit organization that provides a management system to develop published technical information. ASTM standards, test methods, specifications and procedures are recognized as definitive guidelines for motor fuel quality as well as a broad range of other products and procedures.
American standard pipe thread
Type of screw thread commonly used on pipe and fittings to assure a tight seal.
Dimensional standards for fasteners, etc., developed by the American Society of Mechanical Engineers. (ASME)
An alloy of silica and hydrogen, with a disordered, noncrystalline internal atomic arrangement, that can be deposited in thin-film layers (a few micrometers in thickness) by a number of deposition methods to produce thin-film photovoltaic cells on glass, metal, or plastic substrates.
Uncommon abbreviation for ampere. It is preferred to use A
The strength of an electric current in amperes. Electron or current flow of one coulomb per second past a given point in circuit.
The strength of an electric current in amperes.
(A) A unit of measurement used in expressing the rate of electrical current flow in a circuit. It is determined by dividing the voltage by the resistance.
A unit of electric current equivalent to flow of one coulomb per second, where a coulomb is the quantity of electricity which must pass through a circuit to deposit 0.0011180 grams of silver from a solution of silver-nitrate.
The unit of measurement of electrical current produced in a circuit by 1 volt acting through a resistance of 1 Ohm.
That current which, if maintained in two parallel conductors of infinite length, of negligible cross-section, and placed one metre apart in vacuum, would produce between the conductors a force equal to 2×10-7Nm-1.
Measurement of the ability of a battery to deliver a stated amount of current for a stated period of time. The higher the amp/hr. rating, the more powerful the battery.
Unit of charge equal to 3600 coulombs or 1 ampere flowing for one hour.
Ampere hour capacity
A measurement of storage battery’s ability to deliver a specified current over a specified length of time.
In an accumulator, the ratio of the ampere-hour output during discharge to the ampere-hour input during charge.
(Ahm) An instrument designed to monitor and record the product of electrical current and time (ampere-hours) for a given circuit or passing at a given point. If the voltage is constant, the meter can be calibrated as an energy (kilowatt-hour) meter.
The relation between the magnetizing field H around a conductor, length l, carrying a current i, given by the formula
The magnetomotive force produced by a current of one ampere in a coil of one turn
A term used to measure magnetic force. Represents product of amperes times number of turns in coil of electromagnet
Rule giving the direction of the magnetic field associated with a current. If the conductor is grasped with the right hand, the thumb pointing in the direction of the current, the fingers will curl around the conductor in the direction of the field. Also called right-hand rule.
Ampère’s theory of magnetization
A theory based on the assumption that the magnetic property of a magnet is due to currents circulating in the molecules of the magnet.
(At) SI unit of magneto-motive force, which drives flux through magnetic circuits, arising from one ampere flowing around one turn of a conductor.
Ampere-turn amplification, gain
Ratio of the load ampere-turns to the control ampere-turns in a magnetic amplifier.
Term used to measure magnetic force. Represents product of amperes times number of turns in coil of electromagnet.
Ampere-turns per meter
SI unit of magnetizing force, magnetic field intensity.
Measurement of the ability of a battery to deliver a stated amount of current for a stated period of time. The higher the amp/hr. rating, the more powerful the battery.
A device used to increase the electron flow in an electric or vacuum circuit. It produces a greater electrical signal such as the radio signal. Most automobile radios have a built-in amplifier; but a few have a separate amplifier which is sometimes located in the trunk.
Abbreviation for Air Management Unit — An assembly of pressure switches, and other valves located in a chassis cross-member, designed to control the pneumatic accessory functions of a vehicle using the multiplex electrical system.
Abbreviation for Association of Motor Vehicle Importers Representatives (Greece).
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An automobile manufactured by AMC. The 1968-70 models are milestone cars.
A bolt used to secure frameworks, stanchion bases, etc. to piers or foundations, and having usually a large plate washer built into the latter as anchorage
The bolt which goes through a bracket to secure something. British term is through bolt.
A fitting attached to the overhead contact wire of a tramway or railway to support the wire, and also to take the longitudinal tension and prevent movement of the wire in a direction parallel to the track.
A heavy gate, such as a canal lock gate, which is supported at its upper bearing by an anchorage in the masonry such as an anchor bolt.
The stationary portion of a duo-servo drum brake on which the tops of the brake shoes rest. The secondary shoe bears against the anchor pin when the brakes are applied and the vehicle is moving forward. Conversely, when the vehicle is backing up and the brakes are applied, the primary shoe bears against it.
The point in a drum brake system where the braking forces are transmitted to the axle and which prevents the brake shoes from revolving with the drum.
The stationary portion of a leading/trailing drum brake on which the heels of the brake shoes ride.
A bracket, solidly attached to the vehicle suspension, on which a floating or sliding caliper mounts
A male veteran bicycle rider who has completed a 1200 kilometre randonnée.
A female veteran bicycle rider who has completed a 1200 kilometre randonnée.
The various components attached to the main part of the engine and driven by the engine itself — such as the alternator, generator, power steering pump, supercharger, fuel pump, and water pump.
Instrument for measuring the rate of airflow or motion.
Aneroid altitude compensator
A bellows device, installed integrally with the APT system on some post-1975 Rochester Quadrajet carburetors, that automatically compensates for changes in altitude by raising or lowering the primary metering rods, thus richening or leaning out the air/fuel mixture in accordance with changes in air pressure.
A device to determine atmospheric pressure with the use of a vacuum chamber or syphon bellows
An older style thermostat located in the engine coolant system. It has a metal expandable bulb partially filled with acetone, alcohol, or another volatile liquid. As the coolant reaches operating temperature, the liquid in the bulb will boil and expand the bulb, closing the valve to allow coolant to the radiator.
A bulldozer with a blade able to be set in such a way to push material to the side of the road. Usually called a grader or motor grader.
The vertical angle measured above the horizontal, from the surveyor’s instrument to the point observed.
A power tool (driven by electricity or compressed air) which has abrasive discs. The tool helps to remove old paint or rough metal surface
Mild steel bar rolled to an L-shaped cross-section, used in structural work. Legs may be equal or unequal and leg lengths up to 800 mm are available. Also called angle, angle bar, angle steel, and L-iron.
A compression ring where the open ends meet with a matching 45° angle.
A pair of pliers with long jaws that are bent at right angles to aid in gripping something which cannot be reached with regular pliers.
Angle of advance
The angle in excess of 90° by which the eccentric throw of a steam-engine valve gear is in advance of the crank.
The angle between the position of ignition and outer dead center in a spark-ignition engine, optimizes combustion of the fuel.
Angle of attack
The angle between the chord line of an airfoil and the relative airflow. Also called (in error) angle of incidence.
Angle of contact
The angle subtended at the center of a pulley by that part of the rim in contact with the driving belt.
Angle of Flex
The total angle of chain joint articulation as a chain enters or leaves a sprocket or wheel. The angle is equal to 360 degrees divided by the number of teeth in the sprocket.
Angle of Head
In countersunk heads, the included angles of the conical underportion or bearing surface, usually 82 or 100 degrees.
Angle of lock
The angle between the line through the center of the wheel seen from above when turning a corner and the same line when going straight.
A compound that does not contain any water. Ethanol produced for fuel use is often referred to as anhydrous ethanol, as it has had almost all water removed.
Anhydrous calcium sulphate
Dry chemical made of calcium, sulphur, and oxygen (CaSO4)
An oily liquid poisonous (C6H5NH2) obtained especially by the reduction of nitrobenzene and used chiefly in organic synthesis (as of dyes)
The aniline point of a petroleum product is the minimum equilibrium solution temperature with an equal volume of freshly distilled aniline.
The characteristic of something (like a crystal) that when light or magnetism passes through it from one angle, it gives a different reading or measurement than when measured from a different angle because the molecules are arranged in a regular lattice which allow or inhibit the light or magnetism.
To remove hardness from metal by heating, usually to a red color, then allowing it to cool slowly. Unlike steel, copper is annealed by heating, and then plunging it into cold water. It is the reverse of hardening.
In an electrical circuit it is the positive pole. It is that part of an electrical circuit to which electrons are flowing.
The electrode at which oxidation occurs. For fuel cells that create potential, it is also the electrode towards which negative ions flow.
The positive terminal of an electrolytic cell
Zinc, aluminum, or an alloy that is attached to the hull of a vessel. As electric current moves from the vessel to the water, the anode is destroyed (oxidized). Without this anode shell, the metal hull plating would be dissolved by electrolysis.
By electrolytic action, this is the process of coating or plating a metal (usually aluminum) with a thin protective film or material such as chrome. It is sometimes applied with colored dye.
An electroplating process commonly performed on aluminum parts, which forms a thin protective film on the surface of the metal. Anodizing is sometimes accompanied by the use of a colored dye, which gives a lustrous colored finish to the aluminum parts.
The process by which a hard, non-corroding oxide layer is deposited on aluminum.
A small auxiliary combustion-chamber, used in some compression-ignition engines, in which partial combustion of the fuel is used to force the burning mixture into the cylinder, so promoting more perfect combustion.
A device which pulls in radio reception. Also called aerial.
Automobiles employ three basic types of radio antennas.
Wires embedded in the glass of the windshield
Power operated staff which rises from the surface of the sheet metal when the radio is turned on, but is lowered almost flush when the radio is turned off. It is usually made up of several sections which telescope together. It is mounted on one of the four fenders. See Power antenna
A one-piece flexible rod or shorter stiff rod which is mounted to the surface of the sheet metal. It is called a ‘fixed-mast antenna’ in contrast to a power antenna. It is usually mounted in one of three basic locations: on either side of the front fender ahead of the A-pillar; either side of the rear fender behind the backlight (i.e., rear window); on the front or back of the roof. Fixed-masts are relatively trouble-free, unlike power antennas which rely upon a motor that may fail. However, some fixed-masts are subject to breakage by vandals or car-washes.
Made or generated by a human or caused by human activity. The term is used in the context of global climate change to refer to gaseous emissions that are the result of human activities, as well as other potentially climate-altering activities, such as deforestation.
A resilient coat of paint between the primer and the top coat to protect the body shell from chipping damage caused by gravel or stones.
An area of the earth’s crust where folding has made a dome like shape in the once flat rock layers. Anticlines often provide an environment where natural gas can become trapped beneath the earth’s surface, and extracted.
A dive is the action of the front of the vehicle to point downward during braking. The suspension in cars is designed to remove this tendency.
A sticky material which is applied to the inside of panels to reduce the noise caused by vibration or drumming
A substance applied in paint form to ships’ bottoms and structures subject to the action of sea water, to discourage marine growths.
A chemical (usually ethylene glycol) added to the cooling system to prevent the coolant from freezing in cold weather. It also inhibits the formation of rust and other deposits which may clog the radiator and other cooling passageways. Its resistance to freezing is better with a mix of 50-50 with water than 100% antifreeze.
A bearing containing rollers, needles, or balls plus an inner and outer race. The bearing is designed to roll instead of slide thus minimizing friction between two moving parts. To avoid disintegration, the bearing must use lubrication (i.e., wet friction)
(AKI) The measure of the anti-knock properties of a brand and type of gasoline. It is defined as half the sum of the research octane number (RON) and motor octane number (MON). This is the number posted on the retail gasoline pumps normally indicating 87, 89, or 92 octane. Racing gasoline have AKI’s from 100 to 118.
Substances like lead (IV) ethyl added to fuel to lessen its tendency to detonate or knock in an engine.
The relative immunity of a volatile liquid fuel from detonation in a gasoline engine as compared with some standard fuel.
(ANS) A noise counteraction system. This is a sophisticated system which has a number of small microphones placed around the vehicle to detect driving noises. A computer microprocessor analyzes these noises and generates matching counter-frequencies which are sent to small speakers located in the passenger compartment. In this way the road noises are cancelled or erased.
A device for venting vapors from the main discharge tube, or the well, of a carburetor. The vented vapors are not released into the atmosphere, but rerouted into an evaporative emission canister where they are stored until the next time the vehicle is started. Thus it provides a richer mixture needed for starting.
A vehicle built prior to 1915 sometimes called the brass era because of the widespread use of fancy brass fittings and brass lanterns that were a natural addition to the new ‘horseless carriage.’ The Brass era lasted from around 1905 to 1914. This was the beginning of mass produced affordable vehicles for the common public rather than the domain of the elite.
A vehicle built between 1880 and 1916 (inclusive)
A vehicle (including hardtop or convertible) built before 1950 and in original form with no modern technology, equipment, or refinements except wheels.
Sometimes called the anti-sway bar, stabilizer bar, or even (incorrectly) roll-bar. It is usually a round bar which connects the left wheel suspension assembly with the right side. It may be found at the front and/or rear. Its main function is to keep both wheels rolling at the same rate when meeting bumps; but it also affects handling. A front anti-roll bar increases understeer and a rear bar increases oversteer.
An anti-roll bar yields low roll centers with the attendant advantage of minimum jacking effect due to lateral loading and minimum lateral wheel deflection on the bump — without the disadvantage of large roll angles and consequent camber change.
(ASBS) A computer controlled automotive device which senses when one or more of the wheels are locking up during braking. It eases up on the amount of hydraulic pressure to that wheel. It must be remembered that a wheel cannot be steered unless it is rolling; so if the wheel is locked up, there is no steering control. By the use of electronic computers, the brakes rapidly alternate from full power to none so that both maximum braking and maximum steering control is allowed. If you jam on the brakes, you will feel a pulsing sensation. Sometimes called anti-lock brakes.
A shim (metal plate) placed behind the brake piston or the brake pad to reduce noise when the brakes are applied.
A diaphragm unit mounted on the carburetor that allows air to escape slowly from its vacuum chamber to prevent throttle plate(s) in the carburetor from closing too suddenly–and stalling the engine–during deceleration.
A valve for bleeding off surplus compressor air to suppress the unstable airflow due to surge in a gas turbine engine.
Any device (mechanical or electrical) which tends to reduce the theft of a vehicle. It may involve an alarm system, ignition lockouts, steering locks, steering wheel locks, transmission locks, and/or wheel locks.
An arm, usually with a small wheel attached at the outer end, which is secured to the back of a wheelchair to prevent the chair from falling on its back and thereby injuring the patient.
Because the engine, transmission, differential, and other components tend to vibrate when in motion, noise increases and there is possible wear at the points of contact with the frame members. Rubber blocks are used to cushion the vibration at the mounting points.
Rubber springs designed to absorb vibrations from engines, etc. Care needed in design and materials selection to match vibration frequency with main damping peak of elastomer.
Abbreviation for Association of Automotive Manufacturers and Importers (Romania).
Gravity (weight per unit volume) of oils as measured by the API scale. This standard was adopted by the API 5/4/22 as the standard for the American petroleum industries. The measuring scale is calibrated in terms of degrees API
Abbreviation for American Petroleum Institute scale. Scale of relative density, similar to Baumé scale. Degrees API=(141.5/s)-131s, where s is the relative density of the oil against water at 15°C.
When you look at the side of a car, the pillar that is attached to the windshield and supports the roof is called the A-post or A-pillar. There are two to each car. Generally the middle post is the B-post and the back post is the C-post.
The name of a number of vehicles such as the following:
A compact car based on the GM front engine/rear drive ‘X’ car platform and built by Buick from 1973-75 that was essentially a re-badged Chevrolet Nova like the Oldsmobile Omega and Pontiac Ventura and later the Cadillac Seville.
When you look at the side of a car, the post that is attached to the windshield and supports the roof is called the A-post or A-pillar. There are two to each car. Generally the middle post is the B-post and the back post is the C-post.
The product of the voltage (in volts) and the current (in amperes). It comprises both active and reactive power. It is measured in volt-amperes and often expressed in kilovolt-amperes (k VA) or megavolt-amperes (MVA).
The most sharply angled incline the vehicle can make without its front scraping the ground. Measured in degrees, it’s the angle formed on one side by the horizontal axis, and on the other by a straight line connecting the forward edge of the front tire and the most prominent front-end feature extending beyond that line — the bumper, fog lamps, tow hook, etc.
In side-view, the angle between the ground and a line, ahead of the vehicle, joining the periphery of the front wheel and (typically) the front bumper or other low component. It represents the size or steepness of a slope or obstacle that can be approached or climbed without striking bodywork.
A firm surface of concrete or tarmac laid down adjacent to aerodrome buildings to facilitate the movement, loading and unloading of aircraft.
The area outside the warehouse or loading dock door which is used by delivery vehicles to park or position for loading and unloading. The apron height matches the height of the floor of the trailer and makes it easy to load and unload merchandise.
A faulty paint spraying technique where the spray gun is not moved along the panel surface at a uniform distance. Instead it is moved toward the panel when starting and moved away toward the end of the panel. The result of this technique is an uneven application of paint.
A process where the brake shoes are ground to the proper curvature for the drums they are to be used with. Modern brake shoes are pre-arced.
The electrical current that flows in the armature winding of a DC motor tends to produce magnetic flux in addition to that produced by the field current. This effect, which reduces the torque capacity, is called armature reaction and can affect the commutation and the magnitude of the motor’s generated voltage
A relay operated electromagnetically, thus causing the armature to be magnetically attracted.
The primary shaft on which the armature is mounted in a starter or generator.
The complete assembly of conductors carried on the armature and connected to the commutator or to the terminals of the machine.
Traditionally, specially heavy alloy steel plate hardened on the surface; used for the protection of fighting vehicles and ships. There is also a form of armor plate based on aluminum alloy particularly suitable for fast moving military vehicles.
Panels and glass that are extra thick to be bullet-proof.
British spelling of armor
A projection upon which the occupants can rest or support their arms. Usually located on the door panel and sometimes in the center of the front seats or the center of the rear seat.
Hydrocarbons based on the ringed six-carbon benzene series or related organic groups. Benzene, toluene and xylene are the principal aromatics, commonly referred to as the BTX group. They represent one of the heaviest fractions in gasoline. They are called aromatics because many of their derivatives have sweet or aromatic odors.
A device which prevents a certain action. For example, a spark arrester is a special pipe mounted in the end of the exhaust pipe which prevents any burning gasses from coming out with the possible danger of igniting any combustibles in the area (i.e., setting the forest on fire).
Abbreviation for Air Ride Suspension — a suspension system in which the load is supported on air-filled rubber bags rather than steel springs. The engine’s air compressor fills the reservoir tanks which supplies air for the suspension and the air brake system.
Abbreviation for Automatic Restraint System
A major thoroughfare, used primarily for through traffic rather than for access to adjacent land, that is characterized by high vehicular capacity and continuity of movement.
Jointed. An articulated rod is made of two sections with a moveable joint which permits its shape to go from perfectly straight to right angle.
A large public passenger bus, usually more than 55 feet in length, with two connected passenger compartments with an accordion-like section between them which flexes or bends to allow the bus to turn sharply around curves or corners as it bends at that part of the bus. Also called an accordion bus, bendy bus, banana bus, caterpillar bus, double bus, slinky bus, stretch bus, tandem bus, or wiggle bus.
A term used where parts are connected by links and links are anchored to provide a double hinging action.
Two-piece pistons incorporating an entirely separate piston crown or dome with a separate skirt, and linking the two together with the piston pin. Many 1994 and later engines incorporate steel crown/aluminum skirt articulated pistons.
A large truck with two sections to allow it to turn sharply around corners.
The space between the power unit and trailer that allows the combination to pivot and turn corners.
The ability of one axle to move — left wheel up, right wheel down or vice versa — relative to the chassis or its corresponding axle. It is a measure of the ease with which off-road wheels can maintain traction and control in excessively rough terrain.
The action of a chain joint flexing from the straight to an angle and back to straight, as the joint enters and leaves the sprocket or other path, causing it to flex.
See Longitudinal articulation angle, where wheels run within rigid casings without joints to allow vertical hinging as with independent suspension. In an off-road vehicle rigid axles have the advantage of maintaining maximum under-axle ground clearance at all times and always keeping the tire tread flat on the ground.
Formerly, abbreviation for American Standards Association. Now known as American National Standards Institute.
Abbreviation for Air Suspension Automatic Ride Control
A heat resistant and non-burning fibrous mineral (in combination with bonding materials like asphalts and resins) widely used for brake shoes, clutch linings, etc. Asbestos is a health hazard and the dust created by brake systems should never be inhaled or ingested.
A group of naturally occurring minerals that separate into long, thin fibers.
Something that has no asbestos — especially brake and clutch linings.
An incurable lung disease caused by the inhalation of asbestos fibers over an extended period of time.
Sheet metal screws with sharp-pointed ends, fewer threads per inch than type AB screws, and deeper threads with better gripping power than type AB. The Industrial Fasteners Institute incorrectly labels type A an ‘obsolete’ thread though it is universally preferred in 18-8 stainless over type AB, especially by the marine industry.
Inorganic residue remaining after ignition of combustible substances determined by definite prescribed methods.
A frame of a car made of wood from the ash tree and covered with aluminum panels.
A device (in a vehicle) for holding cigarette ashes.
Abbreviation for Automotive Service Industry Association
Abbreviation for Acceleration Simulation Mode
Abbreviation for American Society of Mechanical Engineers
Abbreviation for Advance Shipping Notice which is sent to the warehouse to indicate that a shipment is on its way.
Abbreviation for Air Sensor Potentiometer
The ratio of length to width of rectangular air grille or duct.
The relationship in a tire or wheel between the distance from the rim to the tread and the tire’s width (i.e., ratio of section height to section width). Thus, in a P185/80R13 tire, 80 is the aspect ratio, showing the height is 80% of the width. A lower aspect ratio describes a shorter, wider tire.
In a wing, it is the relationship of its span (horizontal length) to its chord (height). Important for induced drag and range/speed characteristics. Defined as S²/A where S is the span and A is the area. Normal figure between 6 and 9, lesser values than 6 being low aspect ratio, greater than 9 high aspect ratios.
Ratio of the length of a fiber or wire to its width or diameter.
(AR) Ratio of the width to the height of the reproduced picture or computer screen, e.g., 4×3, often expressed with the height as unity. 1.331. Wide-screen systems have aspect ratios between 1.651 and 2.351.
In a Tokamak type of fusion machine, the ratio of the major to minor radii of the torus.
A bituminous substance found naturally in oil-bearing strata from which the volatiles have evaporated
A residue in petroleum distillation
A mixture of asphaltic bitumen and granite chippings, sand, or powdered limestone. Asphalt is used extensively for paving, road-making, damp-proof courses, in the manufacture of roofing felt and paints and as the raw material for certain molded plastics.
A dark brown-to-black cement-like material obtained by petroleum processing and containing bitumens as the predominant component; used primarily for road construction. It includes crude asphalt as well as the following finished products cements, fluxes, the asphalt content of emulsions (exclusive of water), and petroleum distillates blended with asphalt to make cutback asphalts. Note The conversion factor for asphalt is 5.5 barrels per short ton.
Insoluble, semi-solid, or solid particles which are combustible and are highly aromatic. Asphaltenes contain a high carbon to hydrogen ratio and entrap water, fuel ashes and other impurities.
(AC) A mixture of asphalt cement, graded aggregate, mineral filler, and additives.
A new layer of asphalt is placed on the road, making it look brand new. First a layer of liquid asphalt or tack coat is sprayed on the road. Next, fabric may be placed on any badly broken areas for added strength. Finally hot asphaltic concrete is applied, raked and rolled to a prescribed density. Work moves quickly and you can drive on the new asphalt as soon as the rolling is complete. The work must be done when the ground is dry and reasonably warm.
Asphalt concrete placed on the roadway with a paver. Overlays can be anywhere from 25mm to 15cm thick. Thick overlays are typically placed in two to three layers. The work will take anywhere from a day or two, up to a week or two depending on the thickness and the distance to be covered.
A device which is energized by ingesting air (usually oxygen).
To draw into or from a cylinder by suction. The normally aspirated engine operates only on its ability to create a vacuum in the cylinder to bring in air, as compared to the turbocharged engine which pumps in air.
The action of putting something together from a number of component parts.
The finished union of a number of parts to make a component.
Construction of product from several or many components. Methods used for attachment include welding, fastening, push-fit, snap-fit, lock-fit, adhesive bonding, ultrasonic welding, etc. Many products are now designed for robotic assembly.
Natural gas that occurs in crude oil reservoirs either as free gas (associated) or as gas in solution with crude oil (dissolved gas).
Association of American Battery Manufacturers, Inc.
Association of South East Asian Nations
(ASEAN) An organization of states (including Brunei, Myanmar (Burma), Indonesia, Laos, Malaysia, the Philippines, Singapore, Thailand, and Vietnam) founded in 1967 to present an united front that addresses the political, economic, and strategic dynamics of the region.
A pattern in which one side does not correspond to the other side.
A pattern in which one side does not correspond to the other side. Also called dissymmetrical or non-symmetrical.
A headlight system in which one beam is of greater intensity than the other.
Asymmetrical power distribution
A system in a four-wheel vehicle in which more power is transmitted to the front wheels than the rear wheels or more to the rear wheels than the front wheels.
The tread of a tire which has different shapes/patterns and sizes of grooves in the same tire. Often they are divided into three distinct patterns The outside shoulder, the center zone, and the inside shoulder. The outside shoulder tread will have larger shoulder elements with very few sipes to provide increased cornering stability. The center tread zone enhances steering control. The inside shoulder tread zone provides additional traction because the shape of the tread elements, sipes and larger shoulder slots help disperse water and slush. Obviously these tires must be mounted only one way so that the outside pattern is actually on the outside of the wheel.
A wheel rim where the well is located outside the centerline of the wheel. Opposite of symmetric rim.
Abbreviation for Automatic Transmission
Abbreviation for American Trucking Association — a national federation of independent and autonomous truck carrier conferences and state trucking associations. Includes Regular Common Carrier Conference, National Tank Truck Carriers Conference.
Abbreviation for Air Transport Association
Abbreviation for all-terrain bike. Sometimes called MTB (mountain bike), but ATB is the preferred Abbreviation.
Abbreviation for Automatic Traction Control — an optional feature based on ABS which prevents spinning of the drive wheels under power on slippery surfaces by braking individual wheels and/or reducing engine throttle. Also called ASR, an Abbreviation sometimes loosely translated from the German as anti-spin regulation.
The study of how sound is transmitted in the air at different altitudes, weather, humidity, and atmospheric pressure.
Air under the prevailing atmospheric conditions.
The gradual eating away of metal caused by the action of the gaseous elements in the atmosphere including oxygen’s rusting action on iron and the effects of acid rain
Atmospheric crude oil distillation
The refining process of separating crude oil components at atmospheric pressure by heating to temperatures of about 316°C to 400°C (depending on the nature of the crude oil and desired products) and subsequent condensing of the fractions by cooling.
Atmospheric distillation unit
The primary distillation unit that processes crude oil (including mixtures of other hydrocarbons) at approximately atmospheric conditions. It includes a pipe still for vaporizing the crude oil and a fractionation tower for separating the vaporized hydrocarbon components in the crude oil into fractions with different boiling ranges. This is done by continuously vaporizing and condensing the components to separate higher oiling point material. The selected boiling ranges are set by the processing scheme, the properties of the crude oil, and the product specifications.
Atmospheric dust spot efficiency
A measurement of a device’s ability to remove atmospheric air from test air
Earliest form of practical steam engine, in which a partial vacuum created by stem condensation allowed atmospheric pressure to drive down the piston.
Atmospheric gas-burner system
A natural-draft burner injector, in which the momentum of the gas passing into the injector throat inspirates part of the air required for combustion.
The force due to atmosphere per unit area. Atmospheric pressure at sea level is 14.7 psi absolute; it decreases as altitude increases.
The pressure of the weight of air and water vapor on the surface of the earth at sea level, namely 760 mm mercury column or 101.3 kPa.
Atmospheric pressure sensor
A detection device that measures atmospheric pressure. This allows the computer to change engine output in relation to atmospheric pressure and engine vacuum.
Atmospheric-suspended power chamber
A booster power chamber with atmospheric pressure on both sides of its diaphragm when the brakes are not applied.
Abbreviation for Advance Traffic Management Systems
The basis of all matter. It consists of a nucleus made up of protons and neutrons, and one or more orbiting electrons.
The angle of the rear spoiler where it is most effective against lift.
Parking which is left to a valet and supervised by an attendant.
Attenuated total reflection
Spectroscopic method of analyzing thin films on reflective substrates, esp. using infrared radiation.
A reduction of noise or emission.
General term for reduction in magnitude, amplitude, or intensity of a physical quantity, arising from absorption, scattering, or geometrical dispersion. The latter, arising from diminution by the inverse square law, is not generally considered as attenuation proper.
The coefficient which expresses energy losses of electromagnetic radiation due to both absorption and scattering in a medium. Relevant to narrow beam conditions. Also called total absorption coefficient
The use of networks to correct for frequency-dependent attenuation, e.g., in transmission lines.
The real part of α in the relationship ρ=ρe– αx, where ρ is a physical quantity, such as the amplitude of a wave propagating along a transmission path, and x is the distance along the path. The imaginary part of α is known as the phase constant. More simply, but less commonly defined by μ = αλ where μ is the attenuation and λ is wavelength, i.e., α is the attenuation per wavelength distance of propagation.
Distortion of a complex waveform resulting from the differing attenuation of each separate frequency component in the signal. This form of distortion is difficult to avoid, e.g., in transmission lines.
Attenuation of X-rays
Absorption and scattering of X-rays as they pass through an object.
An arrangement of fixed or variable resistive elements designed to reduce the strength of any signal (audio- or radio-frequency) without reducing appreciable distortion. Attenuators also incorporate impedance matching to the transmission lines or circuits to which they are connected, regardless of the attenuation they introduce. For lower frequency applications they may be simply variable or fixed resistances, for high frequencies they may be pieces of resistive material, introduced into transmission lines, stripline, or waveguide. Fixed attenuators are sometimes referred to as pad.
The construction of a vehicle which gives the appearance of a particular characteristic which may be aggressive, intimidating, playful, cheerful, etc.
The overall relationship of a vehicle to the ground
Of an aircraft in flight, the angle made by its axes with the relative airflow; the aspect is the angle made by its axes with the ground when the aircraft is on the ground.
A gyro horizon which indicates the true attitude of the aircraft in pitch and roll throughout 360° about these axes.
Fundamental instrument in which potential is measured by the attraction between two oppositely charged disks.
A process of wearing out an object by friction.
A test for the determination of the wear-resisting properties of stone, particularly stone for road-making. Pieces of the stone are placed in a closed cylinder, which is then rotated for a given time, after which the loss of weight due to wear is found.
Abbreviation for All Terrain Vehicle — a vehicle designated for all types of ground surface.
Abbreviation for Automatic Transaxle
At your back door
Trucker slang for behind your truck as in ‘Smokey’s at your back door.’
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A vehicle brand of which all 8 and 12-cylinder models are classic cars.
A style of group bicycle touring found in Europe (esp. France) where a road captain sets a steady pace for a group of riders. All riders are to finish together, but (unlike regular randonneuring) a sag wagon is permitted.
Audax Club Parisien
A cycle-touring club in Paris, France which begun in 1904 to promote the Audax style of
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A German automobile manufacturer which began in 1899 has four interlocking rings as its emblem. These rings represent the 1932 union of four automakers (Audi, DKW, Horch, and Wanderer). Later NSU joined in 1969. Audi was owned by Daimler-Benz from 1958 to 1965, and then by Volkswagen. It includes the following:
Ability to be heard; said of faint sounds in the presence of noise. The extreme range of audibility is 20-20,000 Hz in frequency, depending on the applied intensity; and from 2 x 10-5Nm-2(ms) at 1000 Hz (the zero of the phon scale, selected as the average for good ears) to 120 dB.
Audible ringing tone
An audible tone fed back to a caller as an indication that ringing current has been remotely extended to the called subscriber’s telephone. On circuits in UK it is heard as a double beat recurring at 2 second intervals. Also called Audible signal
Body overseeing public sector finances and service delivery.
A shaft with a broad spiral flange rotating inside a cylindrical casing to carry bulk material from one end of the shaft to the other. Augers are used to unload cargoes such as grain from grain trailers.
For an atom which has been ionized by the ejection of an inner electron, the loss of energy by the ejection of an outer electron. Energies of the Auger electrons emitted are characteristic of the atomic energy levels, provided a method of determining surface composition and character.
For a given excited state of an atom of a given element, the probability of de-excitation by Auger process instead of by X-ray emission.
Means of increasing forces by afterburning in a gas turbine.
Means of increasing forces by induced airflow in a rocket.
Means of increasing forces in a wing of STOL aircraft by ducting compressed air flow from a gas turbine into circulation-increasing slots and flaps to create high lift coefficients, thereby giving slow landing speeds.
Luminous glow from the outer portion of electric arc which has a spectrum different from that of the highly-ionized core.
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A model of automobile built by Oldsmobile from 1995-2003
Zone where radio transmission is affected by aurora
The higher density, high-temperature, face-centered cubic, γ form of iron and of solid solutions based on it. In pure iron it is stable between 1183°K and 1663°K.
A type of stainless alloy named for Sir Robert Williams Austen, an English metallurgist.
A sealable high-pressure container used for polymerization and in tire production.
Auto coarse pitch
The setting of the blades of a propeller to the minimum drag position if there is a loss of engine power during take-off
An instrument for accurately measuring small changes in the inclination of reflecting surfaces. Principally used for engineering metrology measurements.
A convex mirror used to produce a parallel beam of light from a reflecting telescope. It is placed at the focus of the main mirror.
Technique for detecting weak signals against a strong background level. Signal is subjected to controlled delay, the original delay signals then being fed to the autocorrelation unit which responds strongly only if delay is an exact multiple of signal period.
A timed competition of low-to-medium speed driving, with one driver at a time navigating a small course defined by traffic cones. drivers compete against one another for the fastest timed lap (sometimes multiple laps) through the course.
A visual prompter which displays a script to persons in front of a TV camera. Normally mounted on the camera to give eye contact with the viewers.
An obsolete moped which is a form of a light motorcycle with a small engine (usually below 100cc) that uses pedals to start the engine and provide some extra help getting up hills.
A retail outlet that carries one (or in some cases in the U.S., a number of) manufacturer’s product line and sells to general consumers and fleet operators. The outlet will also provide service and sell parts for the brand of vehicle that it carries. In some instances, a dealer may dual for another manufacturer’s product line.
A retail outlet that carries one (or in some cases in the U.S., a number of) manufacturer’s product line and sells to general consumers and fleet operators. The outlet will also provide service and sell parts for the brand of vehicle that it carries. In some instances, a dealer may dual for another manufacturer’s product line.
Term describing an electrical circuit in which the same elements and valves are used both as oscillator and detector. Also called endodyne, or self-heterodyne.
A receiver using the principle of beat reception and including an autodyne oscillator.
An automatic landing system which operates on the flare-out part of the landing, using an accurate radio-altimeter.
Device which improves autofocus performance in low light by projecting a high contrast light pattern onto the subject.
Brake adjusters that are actuated by the application of the park brake or by normal brake operation to compensate for lining wear. At one time, in order to activate the brake adjuster, it was necessary to operate the vehicle in reverse and hit the brakes.
Brake adjusters that are actuated by the application of the parking brake or by normal brake operation, to compensate for lining wear.
A mechanism which adjusts the ignition advance by means of centrifugal weights or by a diaphragm controlled by intake manifold vacuum.
An air-conditioning system which automatically maintains a preset temperature.
A heating and ventilation system which automatically switches to the recirculation mode when the pollutant levels of the air inside the vehicle exceed certain levels; but after a certain period of recirculation, opens the intake air doors again to let some fresh air in, even if its quality is still questionable.
Automatic arc lamp
An arc lamp in which the feeding of the carbons into the arc and the striking of the arc are done automatically, by electromagnetic or other means.
Automatic arc welding
Arc welding carried out in a machine which automatically moves the arc along the joint to be welded, feeds the electrode into the arc, and controls the length of the arc.
Automatic beam control
(ABC) System in a TV camera which momentarily alters the beam current in the camera tube to reduce the tailing effects on moving highlights. Also called automatic beam optimizer
Circuit used in some television receivers to keep average brightness levels of screen constant
Automatic call distribution
An intelligent network service which takes account of factors such as time of day or caller location to route calls to the appropriate point within an organization.
Camera in which the focus lens aperture and shutter speed are selected automatically, film advance by motor drive may also be included. Priority selection may be available, for example, exposure based on either general or spot areas and with aperture or shutter speed limitations.
A device attached to the carburetor that automatically reduces the amount of air entering the carburetor by sensing changes in engine temperature. It is usually controlled by a coil spring which changes length as the engine is warmed or cooled.
A circuit breaker which automatically opens the circuit as soon as certain predetermined conditions (e.g., an overload) occur.
Automatic closing system
A system which automatically closes the doors, windows, sunroof, trunk, and hood.
Automatic contrast control
Form of automatic gain control used in video signal channel of a television receiver.
Valve action reached through self-operated or self-actuated means, not requiring manual adjustment.
Switching system which operates control switches in correct sequence and at correct intervals automatically.
Control system incorporating servomechanism or similar device, so that feedback signal from output of system is used to adjust the controls and maintain optimum operating conditions.
Automatic Cruise Control
(ACC) A term found on a cruise control witch which indicates the direction the switch needs to be moved to increase the speed (accelerate) of the vehicle
A term frequently applied to a small automatic circuit breaker suitable for dealing with currents of a few amperes.
System of removing ice and frost from evaporators automatically.
Automatic direction finding
(ADF) Airborne navigational aid tuned to radio source of known position. Using rotatable loop aerial mounted above in aircraft to detect the direction of the radio source by rotating until the signal is zero.
Automatic expansion valve
(AEV) pressure-controlled valve which reduces high-pressure liquid refrigerant to low-pressure liquid refrigerant.
(AE) A control system using a photosensor in the camera to measure scene brightness and automatically set the lens aperture/shutter speed combination. Refinements include measuring particular areas of the scene and program exposure modes. A video camera uses the video signal to determine exposure.
Automatic flight control system
(AFCS) A category of automatic pilot for the control of an aircraft while en route. It can be monitored by speed and altitude data signals, signals from an instrument landing system and VOR, has automatic approach capability, and is disengaged before landing.
(AF) Control system for automatically setting the lens focus to the subject distance; in a simple form, this may be by means of coupled range-finder but advanced types employ completely automatic examination of the image. In an enlarger or rostrum camera, lens focus is mechanically set by the distance from the base.
Automatic four-wheel drive
(A4WD) A driving system that automatically engages 4WD as needed, usually by monitoring differences in individual wheel speeds and thus sensing when a tire is slipping.
Automatic frequency control
(AFC) FM stations tend to drift a little, so radios have incorporated the frequency control to maintain the desired frequency automatically.
Automatic frost control
Control which automatically cycles refrigerating system to remove frost formation on evaporator.
Automatic gain control
(AGC) System in amplifiers which compensates for a wide range of input signals to give a more uniform level of output and thus accommodate for a wide range of conditions including fading, masking of antenna, and ambient light.
A small generating station, e.g., a gasoline or diesel driven generator and battery which is automatically started when the battery voltage falls below a certain value and stopped when it is fully charged. The term is also applied to the plant in small unattended hydroelectric generating stations.
Automatic ice cube maker
Refrigerating mechanism designed to automatically produce ice cubes in quantity.
Rapid, out of control combustion of the air-fuel mixture in a spark ignition engine, but not caused by an external ignition source such as a spark or flame; instead, it’s caused by a hot spot such as a carbon deposit in the roof of the combustion chamber. Also called auto-ignition.
Ignition of fuel at the burner when the fuel controlling device is turned on, including reignition if the flames on the burner have been extinguished by means other than by the closing of the fuel controlling device.
Automatic ignition system
A system designed to ignite and re-ignite a main burner.
Automatic level control
A component of the suspension which raises or lowers either (or both) the front or rear of the vehicle when there is a change in the amount of load in the vehicle.
Automatic mixture control
A device for adjusting the fuel delivery to a reciprocating engine in proportion to air density.
An automobile radio which cancels noise output when you turn the station dial.
An apparatus for recording, photographically or electronically, the indications of a large number of measuring instruments on experimental research aircraft.
A parachute for personnel which is extracted from its pack by a static line attached to the aircraft.
Automatic phase control
In reproducing color TV images, the circuit which interprets the phase of the chrominance signal as a signal to be sent to a matrix.
A device for guiding and controlling an aircraft on a given path. It may be set by the pilot or externally by radio control. Also called autopilot. Colloquially called George
Automatic quiet gain control
Joint use of automatic gain control and muting
Automatic reel change
On rotary machines, equipment to attach a new reel to an old web, without stopping the machine and severing the butt end of the old web. Also called autopaster or flying paster.
Automatic ride control
Electronically operated soft or firm ride as required.
Automatic screw machine
Fully automatic single-spindle or multiple-spindle bar stock turret lathe.
In a film projector, a shutter which cuts off the light when the mechanism stops, to protect the film from heat.
A system of railway signaling, usually with electric control, in which the signals behind a train are automatically put to danger as soon as the train has passed, and held in that position until the train has attained the next section of line.
Automatic slip-control differential
(ASD) An electronically controlled, automatic locking differential developed by Mercedes-Benz.
A starter for an electric motor which automatically performs the various starting operations (e.g., cutting out steps of starting resistance) in the correct sequence, after being given an initial impulse by means of a push-button or other similar device.
Automatic steering effect
Built in tendency of an automobile to resume travel in a straight line when released from a turn.
A substation containing rotating machinery which, as occasion demands, is started and stopped automatically, e.g., by a voltage relay which operates when the voltage falls below or rises above a certain predetermined value.
A device which performs the process of synchronization in an AC circuit automatically
Automatic tap-changing equipment
A voltage-regulating device which automatically changes the tapping on the winding of a transformer to regulate the voltage in a desired manner.
Automatic temperature control
A system which regulates the heater and air conditioner so that the temperature inside the vehicle meets the preset temperature.
Automatic test equipment
(ATE) An electronic equipment for testing ignition, wiring, fuel injection systems, etc.
Servo control of radar system operated by a received signal, to keep antenna aligned on target.
Automatic Traffic Counter
An electric or mechanical device which determines (i.e., counts) how many vehicles pass a certain point on a designated road.
Automatic train stop
A catch, used in conjunction with an automatic signaling system, which engages a trip-cock on the train passes a signal at danger.
A mechanism of the drivetrain which takes the power from the engine and transfers it to the driveshaft or wheels.
Reduction of signal voltage range from sounds which vary widely in volume, e.g., orchestral music. This is necessary before they can be recorded or broadcast but ideally requires corresponding expansion in the reproducing system to compensate.
Automatic volume control
Alteration of the contrast (dynamics) of sound during reproduction by any means. By compression (compounder) a higher level of average signal is obtained for modulation of a carrier, the expansion (expander) performing the reverse function at the receiver. In high-fidelity reproduction, arbitrary expansion can be disturbing because of variation in background noise, if present.
An automobile radio which automatically limits the maximum volume to a preset level.
Expansion of dynamic range, e.g., by keeping peak level constant and automatically reducing the lower levels. Used to counteract loss of dynamic range through studio or recording equipment, or during transmission.
Automatic wear adjuster
A device that automatically compensates for the wear of brakes or clutch.
Welding in which the work, the torch, and/or the arc is mechanically moved and controls are used to control the speed and/or the direction of travel.
Automatic white balance
(AWB) A self-adjusting balancing system which monitors the lighting and corrects for changes in color temperature
Automatic wire stripper
A tool which removes the outer insulation from a wire by automatically adjusting to the size of the wire thus avoiding damaging the wires.
A system of operation of gasoline-electric vehicles in which a battery, connected in parallel with the generator, supplies current during starting and heavy-load periods and is charged by the generator during light-load periods. Also called Pieper system
Four-wheeled passenger motor vehicle having a seating capacity for not more than 10 people. It includes police cars and racing cars but not ambulances, hearses, or trucks. In Britain, the word automobile is not in frequent use and has been replaced by motor car.
A motoring club which provides assistance to drivers including insurance, maps, travel arrangements, etc.
Vehicle classifications for automobiles and light duty trucks issued by the EPA mileage guide book. Almost every year there are small changes in the classifications, therefore the categories change accordingly. The EPA mileage guide can be found at any new car dealership.
A designation of vehicles according to size, manufacturer, style, usage, price, age, modifications, etc. Includes the following:
The manufacturing industry for building automobiles. Also called motor industry.
A plan which a motorist can purchase for his vehicle which will offset the repair costs of a vehicle which has been involved in an accident. Some plans are offered by a government agency while others are run by independent agencies. All plans offer the basic coverage of property damage and public liability. Others offer extra benefits which cover glass damage, theft, vandalism, etc.
Any of the tools used in the construction, maintenance, or repair of automobiles.
Study of self-regulating systems for process control, optimizing performance.
Generally unmanned aircraft operating without external assistance
Auto Pact base year
With respect to the Auto Pact, the 12 month period beginning on August 1, 1963, and ending on July 31, 1964.
Auto Pact Canadian value added
The aggregate of the costs of parts, material, labor costs, and transportation costs that are reasonably attributed to the production of vehicles or parts by manufacturers producing vehicles in Canada.
Trade name of Chrysler Corp for its automobile parts (i.e., AUTOmobilePARts). Chrysler also uses the name Mopar to indicate its motor parts (i.e., MOtorPARts).
Auto parts store
Jobber and retail auto parts stores which primarily sell automotive products and conduct business at the retail level.
A machine which can deliver a curved stereoplate for rotary printing; built to suit the requirements of each particular rotary machine.
Photographic record, usually of a biological specimen, produced by exposure to radiation from self-contained radioactive material which has been injected or absorbed.
Auto-reclose circuit breaker
A circuit breaker which, after tripping due to a fault, automatically recloses after a time interval which may be adjusted to have any value between a fraction of a second and 1 or 2 minutes
A feature on a cassette player which will automatically play the next side of a cassette tape when one side is finished.
The spin; continuous rotation of a symmetrical body in a uniform air-stream due entirely to aerodynamic moments.
Unpowered rotorcraft flight, in a helicopter with engine stopped, in which the symmetrical airfoil rotates at high incidence parallel with the airflow.
A form of dumpy level for rapid operation, in which the essential features are a quick-leveling head, and an optical device which neutralizes errors of leveling so that the bubbles need not be central while an observation is being made.
A place where old and disabled cars and truck go. The parts are removed and sold. Also called an auto graveyard.
Abbreviation for auxiliary usually indicating those terminals on the fuse panel for non-standard equipment.
Additionally, supplementary. Equipment or component that is added to the main propulsion unit.
Auxiliary acceleration pump
(AAP) a pump that increases driveability during cold engine operation by providing an extra amount of fuel to the acceleration nozzle to supplement the main acceleration pump.
Auxiliary air bleeds
Used on some idle systems to add air to the idle system downstream from the regular idle air bleed; they act in parallel with idle air bleed.
Auxiliary Air Control Valve
(AAC) A device which allows air to bypass a closed throttle during engine start and warm-up, in order to maintain a higher idle speed. The auxiliary air valve provides extra air into the intake manifold during cold engine starting for a higher idle speed during warm-up.
Auxiliary air intake
An air intake for accessories, cooling, cockpit air, etc.
Additional intake for turbojet engines when running at full power on the ground, usually spring loaded so that it will open only at a predetermined suction value.
Auxiliary air regulator
A rotary gate valve which stabilizes idle speed during engine warmup
Auxiliary air valve
A device which allows air to bypass a closed throttle during engine start and warm-up, in order to maintain a higher idle speed. The auxiliary air valve provides extra air into the intake manifold during cold engine starting for a higher idle speed during warm-up.
Auxiliary brake light
Additional brake lights mounted at eye level in the rear window or on the rear fenders. They are designed to give a following vehicle more notice of your presence and intention of stopping.
A unit which controls pressure in various portions of the brake system.
Auxiliary drive shaft
A secondary drive shaft which powers the fuel pump, water pump, or distributor.
Auxiliary driving lamp
A light which supplements the headlights such as a fog light or spot light.
Auxiliary driving light
A light which supplements the headlamps such as a fog light or spot light.
Auxiliary drum parking brake
Incorporates an extra parking brake drum inside a rear rotor on some four-wheel drive disc brake systems.
Supports for small machinery, such as winches, condensers, heaters, etc.
An extra gearbox used in conjunction with the main (manual) gearbox to provide an additional range of speeds.
The gauge which indicates compressor inlet pressure on older Chrysler Corporation vehicles with an Evaporator Pressure Regulator (EPR) valve; also used to measure evaporator pressure on some Ford vehicles with a Suction Throttling Valve (STV).
The portion of the roadway adjoining the traveled way for parking, turning, or other purposes supplementary to through-traffic movement.
An extra leaf in a set of leaf springs. Also called helper leaf or helper spring.
Extra illumination device such as fog lights, spot light, and driving lights which are intended to improve visibility under adverse conditions.
A term used in generating-station practice to cover the condenser pumps, mechanical stokers, feed-water pumps, and other equipment used with the main boiler, turbine, and generator plant.
A special winding on a machine or transformer, additional to the main winding.
An apparatus for measuring the magnifying power of an optical system
The amount of product in the warehouse able to be shipped; does not include product designated as damaged, on hold, or pending shipment.
Available power efficiency
The ratio of electrical power available at the terminals of an electroacoustic transducer to the acoustical power output of the transducer. The latter should conform with the reciprocity principle so that the efficiency in sound reception is equal to that in transmission.
Available power gain
The ratio of the available power output of an amplifier to the input power; equal to power gain only when the output of the device or circuit is correctly matched to the load.
A model of automobile manufactured by the Chevrolet division of General Motors from 2004-08. Also includes the Aveo 5.
A calculation in which the mean value or rate is determined. The average speed is determined by dividing the distance by the time (e.g., 273 kilometres divided by 3 hours = 91 kph). Average fuel consumption is determined as a ratio of fuel and distance. In the metric system, this is determined by multiplying the number of litres by 100 and dividing the result by the number of kilometres (e.g., 31.38 litres times 100 divided by 273 kilometres = 11.49 litres / 100 km). In the Imperial system divide the number of miles by the amount of fuel in gallons (e.g., 173 miles divided by 6.9 gallons = 25 mpg).
Loss or damage of marine property, less than total compensation payment in proportion to amount insured.
The current obtained by adding together the products of currents flowing in a circuit and the times for which they flow and dividing by the total time considered. For direct current the average value is constant; for true alternating current, the average value is zero.
Average Daily Traffic
(ADT) The total traffic volume during a given period divided by the number of days in that period.
Average distance traveled
A ratio of the distance traveled over a period of time. For instance during the month of June I traveled 987 miles. My average for the month is (987 divided by 30) 32.9 miles per day.
Average fuel consumption
A ratio of the distance driven over a set period of time divided by the amount of fuel consumed. For example, during the year the car drove 12,000 miles and consumed 500 gallons yielding an average of (12,000/500) 24 miles per gallon. The same information according to the metric system would consider how many litres consumed for each 100 kilometre traveled. 12000 miles is equal to 19,312 kilometres and 500 U.S. gallons is equal to 1894 litres. Thus the metric fuel consumption is 1894 divided by 19312 divided by 100 which results in 9.8 l/100 km.
Abbreviation for Automatic Vehicle Identification — a system combining an on-board transponder with roadside receivers to automate identification of vehicles. Uses include electronic toll collection and stolen vehicle detection.
A digital modulation scheme in which a 1 is represented by a +90° phase transition and a 0 by a -90° transition of the carrier
A high octane fuel used primarily in aircraft but also used in racing vehicles to improve performance. Generally liquid hydrocarbons, because of high heat of combustion per unit of fuel mass (specific energy) and volume (energy density), ease of combustion, moderate volatility and viscosity, and good thermal stability and capacity. Liquid hydrogen and pentaborane (B5H9) have also been used experimentally.
A complex mixture of relatively volatile hydrocarbons with or without small quantities of additives, blended to form a fuel suitable for use in aviation reciprocating engines. Fuel specifications are provided in ASTM Specification D 910 and Military Specification MIL-G-5572. Note Data on blending components are not counted in data on finished aviation gasoline.
Aviation gasoline blending components
Naphthas that will be used for blending or compounding into finished aviation gasoline (e.g., straight run gasoline, alkylate, reformate, benzene, toluene, and xylene). Excludes oxygenates (alcohols, ethers), butane, and pentanes plus. Oxygenates are reported as other hydrocarbons, hydrogen, and oxygenates.
For gas turbine engines, fuel which typically boils over the range 144°C – 252°C. Variants include Jet A-1 (AVTUR), the international jet fuel; Jet B (AVTAG), a blend of naphtha with kerosine now being phased out except for use in cold climates; AVCAT, a naval jet fuel with high flash-point for safety in enclosed spaces in ships; AVPIN, an aviation isopropyl nitrate; and AVGARD, trade name for an additive with anti-misting properties.
Abbreviation for Automated Vehicle Location — a class of technologies designed to locate vehicles for fleet management purposes and for stolen vehicle recovery. Infrastructure can be land-based radio towers or satellites.
A pointed or flat tool used to probe nail holes and injuries as well as for installing a repair plug.
A canvas roof which is stretched out from a parked trailer or camper to give protection from the sun and rain.
A superstructure deck, as the name implies. In its simplest form, it is the top deck of a two-deck ship, and places the ship in a certain category for scantling and freeboard.
Abbreviation for Automatic 4-Speed Transmission
Trade name for a range of digital switches manufactured by the Swedish company I. M. Ericsson Telefonaktiebolaget.
Plural of axis. When describing points on the body of a vehicle, they can be named from three parameters: its length (longitudinal), height (vertical), and width (cross-car). These three axes or dimensions are labeled X-Y-Z.
A compressor characterized by the unusual piston arrangement. The pistons are arranged horizontally around and parallel to the crankshaft axis or centerline.
A multistage, high-efficiency compressor comprising alternate rows of moving and fixed blades attached to a rotor and its casing respectively.
Axial cooling fins
Brake drum cooling fins perpendicular to the centerline of the axle.
Turbine engine with an axial-flow compressor.
A compressor in which alternate rows of radially-mounted rotating and fixed airfoil blades pass the air through an annular passage of decreasing area in an axial direction.
Characteristic aero-engine turbine, usually of 1-3 rotating stages, in which the gas flow is substantially axial
The distance from any point on one thread or helix to the corresponding point on the next thread or helix measured along the axis of the screw or helix.
Ratio of major to minor axis of polarization ellipse for e.g., a wave propagated in waveguide, polarized light. Also called ellipticity
The response of a microphone or loudspeaker, measured with the sound-measuring device on the axis of the appearance being tested.
Variation from the plane normal to its axis of a rotating part. Its wobble, rather than its eccentricity. Compare radial runout
Valve in which the electron stream to the anode is controlled by the magnetic field of the heating current
The centerline, whether real or imaginary, around which a thing rotates.
One of the three axes of an aircraft, which are the straight lines through the center of gravity about which change of attitude occurs longitudinal or drag axis in the plane of symmetry (roll); normal or lift axis vertically in the plane of symmetry (yaw); and the lateral or pitch axis transversely (pitch).
Of a lens, the line of symmetry of the optical system; the line along which there is no refraction.
An imaginary line along the center of gravity of the weld metal and perpendicular to a cross section of the weld metal.
An axle is a shaft on which the wheels revolve. A full-floating axle is used to drive the rear wheels. It does not hold them on nor support them. A semi-floating or one-quarter floating axle is used to drive the wheels, hold them on, and support them. A three-quarter floating axle is used to drive the rear wheels as well as hold them on, but it does not support them. A live axle holds the wheels and transmits power to the wheels. A dead axle or beam axle merely holds the wheels, but does not transmit power to the wheels.
A numeric expression such as ‘4×2,’ ‘6×4,’ which describes the total number of wheels followed by the number of driven wheels. Thus ‘4×2’ is a vehicle with four wheels on two axles, but only two wheels (on the one axle) drive the vehicle. In contrast, a ‘4×4’ has four wheels on two axles and both sets of axles drive the vehicle.
An adjustable height tripod used to support a vehicle when working underneath it. Although you can raise the car with the jack, use a pair of axle stands for safety. Also called Jack stand or Safety stand
Distance between centerlines of tire tread measured across axle.
A form of wheel hop which is usually found in live rear axle cars. It occurs when sudden torque loads on the suspension cause the driven wheels to shake violently by slightly rotating the wheels and then springing back.
The part of the axle housing which covers the half-shaft or a tubular rigid axle.
The part of the weight of the vehicle which rests on the wheels of the axle.
Having constant maximum and minimum boiling points.
Example of azeotropic mixture refrigerant R-502 is mixture consisting of 48.8% refrigerant R-22 and 51.2% R-115. The refrigerants do not combine chemically, yet azeotropic mixture provides refrigeration characteristics desired
The angle between the vertical plane containing a line or celestial body and the plane of the meridian, conventionally measured from north through east in astronomical computations, and from south through west in triangulation and precise traverse work.