SAE AS8018A

This AS covers subsonic and supersonic Mach meter instruments which, when connected to sources of static (Ps), and total (Pt), or impact (Pt-Ps), pressure provide indication of Mach number. These instruments are known as Type A. This AS also covers servo-operated repeater or digital display instruments which indicate Mach number when connected to the appropriate electrical output of a Mach transducer of Air Data Computer. These instruments are known as Type B.This Aerospace Standard (AS) specifies the minimum safe performance standards for Mach Meter instruments primarily intended for use in aircraft under standard and environmental conditions.