Selection of Thermocouples for High Gas Temperature Measurement

Better understanding of the limitations of noble and refractory metals and refractory oxides has resulted in the development of many successful techniques for the manufacture and application of thermocouples used in the 2000-4000 F temperature range. However, although such materials are available for thermocouples, the results obtained by those that measure high gas temperatures are often unreliable and therefore little correlation to actual temperatures is obtainable. The experiences reported by the authors here suggest that considerable metallurgical advances must be realized before environmental and material compatibility can be compromised and thus overcome the problems of temperature measurements in the higher ranges beyond 4000 F.