High-Speed Multiple-Point Potentiometer Recorder for Measuring Thermocouple Temperatures During Test-Plane Flights

Measuring exhaust-gas temperatures in flight-testing large planes requires the use of thermocouples of special design and requires also an instrument capable of recording rapidly, accurately, and directly a large number of temperatures. This paper describes a multiple-point, null potentiometer for this purpose. It accommodates 140 thermocouples and records each temperature in 1.63 sec. Flexible arrangements are provided for switching the numerous thermocouples, and this switching may be operated manually by push-button control and also automatically by the recorder. Operating characteristics and performance in flight tests are discussed.