Surface and Gas Temperatures via Multiwavelength Pyrometry

A report describes experiments using multiwavelength pyrometry to determine the surface temperature of the end tip inside a BeO cylinder that is part of a probe designed to measure high-temperature gases. The cylinder is heated by the gas into which it is inserted, and the gas temperature is related to the tip temperature via a mathematical model of the probe. The probe was tested in two atmospheric burner experiments. The measured interior temperatures were 1,360 and 1,745 K. Available temperature information on the burner flame is lower, being at 1,300 and 1,580 K, respectively. This was so because the thermocouples performing the measurement were positioned at the cooler periphery of the jet to avoid being destroyed by hot gases at the burner's central flow, the hot temperature of which the BeO probe was successful in measuring.