Experimental Evaluation of a Dual-Element Transducer for High-Temperature-Gas Measurements

An experimental evaluation was made of a dual element transducer, in which gas-stream temperatures are inferred from simultaneous temperature time measurements of two transducers of equal shape but unequal thermal capacity. The accuracy of the transducer was within or - 6 in measurements from 1950 to 2250 F, which was the best experimental accuracy predicted by an earlier analysis of the concept. A limited number of measurements were made with the transducer directly in an oxy acetylene flame. The indicated flame temperatures were 4700 F and 4789 F, which agree within 5 with measurements made by sodium-line-reversal techniques for equivalent combustion conditions in tests conducted at the University of California. In a third series of tests, the transducer was used to traverse a 2100 F gas stream, and from a single record the temperature profile in the stream was calculated within the accuracy to which the true profile could be established. It is concluded that the dual-element transducer is feasible for all the applications tested. Recommendations are made for continued improvement.