STP1427: Suggestions Towards Improved Reliability of Thermocouple Temperature Measurement in Combustion Tests

    Jones, JC
    Senior Lecturer, University of Aberdeen, Aberdeen,

    Pages: 16    Published: Jan 2003


    Abstract

    Two common forms of combustion testing—oven heating tests for spontaneous combustion propensity of coals and carbons, and temperature measurements in ‘simulated room fires’—are discussed in terms of thermocouple uncertainty. For oven heating tests, radiation effects on thermocouple accuracy are examined and examples, from the recent research literature, of unjustifiable claims of thermocouple accuracy in such tests are given and discussed. For simulated room fires, very detailed calculations based on heat balance at the thermocouple tip are performed, and it is shown how unsuspected radiation effects can entail significant errors. Means of eliminating, or at least of significantly reducing, these errors is given in detail. The approach is applicable to steady or to non-steady conditions.

    Keywords:

    thermocouples, combustion testing, radiation error


    Paper ID: STP10946S

    Committee/Subcommittee: E05.13

    DOI: 10.1520/STP10946S


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