Evaluation of Thermocouple and Thermal Radiation Instrumentation for Measuring Gas turbine Combustor Liner Wall Temperature

Temperature measurement techniques for a practical combustion chamber liner wall were investigated. Fourteen methods fo sheathed thermocouple installations on thin stainless steel plates simulating a combustor liner wall were tested by flowing a hot gas along one side and a cold air along the other side. It was found that the Reynolds numbers of the hot and the cold streams have no significant influence on the errors but every installation method has its particular characteristics for the accuracy of the measurement. It was also found that the radiative measurement of a black coated wall may cause a significant error because there occurs a steep temperature gradient across the coating layer.