SAE AS 414B:2008-02-16

TEMPERATURE INSTRUMENTS (TURBINE POWERED SUBSONIC AIRCRAFT)

This SAE Aerospace Standard (AS) covers two basic types of temperature instruments as follows:

Type I:	Ratiometer type, actuated by changes in electrical resistance of a temperature sensing electrical resistance element, the resistance changes being obtained by temperature changes of the temperature sensing resistance element.
Type II:	Millivoltmeter type, operated and actuated by varying EMF output of a thermocouple, the varying EMF input to the instrument being obtained by temperature changes of the temperature sensing thermocouple.