SAE AS8016A PDF

This AS covers vertical velocity instruments which display the rate of change of pressure altitude of an aircraft, as follows: type A - direct reading, self-contained, pressure actuated; type B - electrically or electronically operated, self-contained, pressure actuated; and type C - electrically or electronically operated, input from a remote pressure sensor.

The range of operation of the instrument and the altitude range when applicable shall be as marked on the instrument face or nameplate.

This Aerospace Standard (AS) establishes the minimum performance standards for vertical velocity instruments for aircraft use.