This standard establishes the essential minimum safe performance standards for exhaust gas temperature instruments primarily for use with turbine powered, subsonic aircraft, the operation of which may subject the instruments to the environmental conditions specified in paragraph 3.3 et seq. The exhaust gas temperature instruments covered by this standard are of the electrical servonull balance type, actuated by varying emf output of one or more parallel connected Chromel-Alumel thermocouples.
SAE AS428-1966 Referenced Document
SAE AIR818 AIRCRAFT INSTRUMENT STANDARDS: WORDING, TERMINOLOGY, PHRASEOLOGY AND ENVIRONMENTAL AND DESIGN REQUIREMENTS FOR*, 1991-05-01 Update
SAE ARP582 Lighting, Integral, for Aircraft Instruments; Criteria for Design