Automatic weighing device is referring to a device that weighs without the intervention of an operator and that follows a predetermined program of automatic processes (Weighing Operations Manual)

Automatic piano is usually electrically-operated, which has the pedals automatically controlled and which has limited suction-level variations. Examples include the Hupfeld Phonoliszt, the Recordo, and the Seeburg Style X. Many expression pianos have separate automatic controls for bass and treble hammer rails.also called as expression piano.

Automated sortation pertains to the non-manual sortation of mail. This sortation uses specialised automated mail processing machinery.

Auto container is described as a container equipped for the transportation of vehicles.

Audio monitor is an audio amplifier and speaker system used to check and listen to audio during a production.

Audio generator refers to a piece of test equipment that produces audio tones from DC to well above human hearing.

Animation camera were specifically designed for photographing frame-by-frame through stop-action lenses thus allowing the camera to capture fractions of movements. The camera is mounted on animation stands so that the media being filmed can be framed in a consistent and sequential manner.

Aneroid barometer is described as a mechanical barometer used to measure air pressure for warnings of changing weather. A barometer is an instrument used to measure atmospheric pressure, usually measured in inches of mercury or millibars.