Improved Electrical Connections for Thin-Film Thermocouples

Improved electrical connections have been developed for thin-film thermocouples used to measure temperatures on the surfaces of ceramic-matrix composite-material specimens during high-temperature tests. In a test, specimens are arranged in a four-sided configuration in a test rig, where they are heated from inside the rig by a flame. Composite specimens have endured up to 3,200 °F (1,760 °C) on the hot sides, while temperatures at electrical connections for thermocouples have reached 1,200 °F (650 °C). Previously, the electrical connections on the thermocouples could not withstand the test temperatures; they failed so frequently that no useful data could be taken. In addition, the design of the electrical connections made it difficult to change specimens in the test rig. The improved electrical connections withstand the test temperatures and make it possible to change specimens easily.