This document has been declared NONCURRENT. It is recommended, therefore, that this document not be specified for new designs. NONCURRENT refers to those documents which have previously been widely referenced and may continue to be required on some existing designs.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.