AB - Engineering Definitions: Updated Periodically

Engineering Definition Starting With "AB"
absolute encoder: An electronic or electromechanical device which produces a unique digital output (in coded form) for each value of an analogue or digital input; in an absolute position encoder, for instance, the position following any incremental movement can be determined directly, without reference to the starting position.

absolute humidity: The weight of water vapour in a gas-water vapour mixture per unit volume of space occupied.

absolute measurement; A measured value expressed in terms of fundamental standards of distance, mass and time.

absolute pressure; The pressure measured relative to zero pressure (vacuum).

absolute stability; A linear system is absolutely stable if there exists a limiting value of the Open loop gain such that the system is stable for all lower values of that gain and unstable for all higher values.

absolute value error; The magnitude of the error disregarding the algebraic sign or, if a vector error, disregarding its direction.

absolute viscosity; A measure of the internal shear properties of fluids expressed as the tangential force per unit area at either of two horizontal planes separated by one unit thickness of a given fluid, one of the planes being fixed and the other moving with unit velocity.

absorbance; An optical property expressed as log (SIT), where T is the transmittance.

absorptance; The fraction of the incident light absorbed.

absorption-emission pyrometer; An instrument for determining gas temperature by measuring the radiation emitted by a calibrated reference source both before and after the radiation passes through the gas, where it is partly absorbed.

absolute pressure; The pressure measured relative to zero pressure (vacuum).

absorption tower; A vertical tube in which a gas rising through a falling stream of liquid droplets is partially absorbed by the liquid.