air-speed indicator

air-speed indicator (ASI)

air-speed indicator (ASI)click for a larger image
An instrument to measure the speed of relative airflow. Pitot pressure (i.e., dynamic and static pressure) is taken into a capsule kept in an airtight case. Static pressure is fed into the case. The capsule is thus affected by dynamic pressure only. This is designated as indicated air speed through a system of gears.
References in periodicals archive ?
Experts said that both the altimeter and the air-speed indicator worked by measuring the difference in pressure between the inside of the plane and the outside; if there was a sudden jump in pressure inside, they could produce readings like the ones captured by the flight data recorder.
Standby instruments: air-speed indicator, altimeter, engine performance indicators, radio frequency indicator and rate-of-climbindicator are being jointly developed by Sextant and VDO.