A glossary entries

A device that converts a control signal and supplied energy into controlled motion, force, torque, pressure, flow, or another physical output.

The reciprocal of impedance, expressing how easily alternating current flows through a circuit, component, or network.

The resistive force exerted by air or another gas on a body moving relative to the flow.

Air emissions are pollutants, vapors, particles, gases, odors, or heat released to the atmosphere from a defined source or boundary.

The distortion that occurs when a signal is sampled too slowly or without sufficient filtering, causing high-frequency content to appear as false lower-frequency content.

The maximum stress permitted in a component or structure under a specified design basis after applying safety factors, code limits, and service conditions.

Electric current whose magnitude and direction vary periodically with time, most commonly as a sinusoidal waveform in power systems.

A signal whose value varies continuously over time, space, or another independent variable rather than being restricted to discrete levels.

Direction-dependent behaviour in a material or medium, where properties such as stiffness, strength, conductivity, permeability, or thermal expansion vary with orientation.

A heat treatment process that uses controlled heating and cooling to change microstructure, reduce hardness, improve ductility, relieve residual stress, or restore workability.

Apparent power is the product of the RMS voltage and RMS current in an AC circuit, representing the total power magnitude that the source must supply and the electrical infrastructure must be rated to carry, regardless of how much of it performs useful work.

The permitted dimensional and geometric variation across multiple parts while still allowing an assembly to fit, move, seal, align, or perform as intended.