DICTIONARY OF AUTOMOTIVE TERMS - "At"

A/T
Acronym for Automatic Transmission
ATA
  1. Acronym for American Trucking Association.
  2. Acronym for Air Transport Association
ATB
ATB

All-Terrain Bike

  1. Acronym for All-terrain bike. Sometimes called MTB (mountain bike), but ATB is the preferred acronym.
  2. Acronym for Aeration test burner

ATC
  1. Acronym for Automatic temperature control.
  2. Acronym for air-traffic control
  3. Acronym 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 acronym sometimes loosely translated from the German as anti-spin regulation.
ATDC
See
After top dead center
ATE
Acronym for Automatic test equipment
ATF
Acronym for Automatic Transmission Fluid
A thread
See
Class A thread
Athwartship
Across the ship, at right angles to the fore-and-aft centerline.
ATIS
Acronym for Advance Traveler Information Systems
ATM
  1. Acronym for Standard atmosphere
  2. Acronym for Actuator Test Mode
Also see
Atmospheric pressure
Atmosphere
See
Atmospheric pressure
Standard Atmosphere
Atmosphere Burner
See Injection burner
Atmospheric acoustics
The study of how sound is transmitted in the air at different altitudes, weather, humidity, and atmospheric pressure.
Atmospheric air
Air under the prevailing atmospheric conditions.
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 engine
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.
Atmospheric pressure
  1. The force due to atmosphere per unit area. Atmospheric pressure at sea level is 14.7 psi absolute; it decreases as altitude increases.
  2. 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 k_Pa.
Atmospheric-suspended power chamber
A booster power chamber with atmospheric pressure on both sides of its diaphragm when the brakes are not applied.
ATMS
Acronym for Advance Traffic Management Systems
Atomic Mass
See
Relative Atomic Mass
Atomization
See
Lateral Atomization Orifice
Rotational Atomization Unit
Atomization characteristics
The ability of an oil to be broken up into a fine spray by some mechanical means.
Atomize
The process of changing liquid to minute particles or a fine spray. The extent to which a spray gun breaks up paint into a fine mist, fog, or spray.
Atomized powder
A powder produced by the dispersion of molten metal or other material by spraying under conditions such that the material breaks down into powder.
Atomizer
A device for producing a fine spray such as used on a paint spray gun.
Atomizing pressure
The pressure needed to atomize a liquid like paint.
ATR
Acronym for Attenuated total reflection
Atramentizing
A corrosion protection process in which steel is coated with phosphate using a zinc phosphate solution at 90°C.
ATS
Acronym for Air temperature sensor
Attachment
A fitting or accessory to be used in conjunction with a tool, such as a grinding disc for use with an electric drill.
Also see
Inner attachment face
Split bearing attachment
Attachment face
See
Inner attachment face
Attack
  1. Chemical corrosion of metal.
  2. To damage something by corrosion.
Also see
Angle of attack
Pickling attack
Attack angle
The angle of the rear spoiler where it is most effective against lift.
Attendant parking
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.
Attenuation
  1. A reduction of noise or emission.
  2. 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.
Attenuation coefficient
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
Attenuation compensation
The use of networks to correct for frequency-dependent attenuation, e.g., in transmission lines.
Attenuation constant
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.
Also see
Decibel
Attenuation distortion
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.
Attenuator
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.
Attitude
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.
Attitude indicator
A gyro horizon which indicates the true attitude of the aircraft in pitch and roll throughout 360° about these axes.
Attracted-disk electrometer
Fundamental instrument in which potential is measured by the attraction between two oppositely charged disks.
Attrition
A process of wearing out an object by friction.
Attrition test
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.
ATV
Acronym for All Terrain Vehicle -- a vehicle designated for all types of terrain
ATX
Acronym for Automatic Transaxle
At your back door
Trucker slang for behind your truck as in "Smokey's at your back door."