1000 HOUR - 2300°C THERMOCOUPLE STABILITY TESTS

摘要

Two 1000-hour stability tests on small diameter (9 mil wires) thermocouples were conducted in a helium atmosphere at 2300°C. The first test used high purity hafnia (HfO2) insulators and W versus W-25Re thermoelements. The second test employed high purity thoria (ThO2) insulators and W-3Re versus W-25Re thermoelements. Both tests completed the 1000-hour test period at 2300°C.nThe W leg of the W, W-25Re thermocouple used with Hf02, was found to be eroded and the W-25Re leg was found to have a higher W content. Both events influenced the emf output of the W, W-25Re thermocouple system.