부산대학교 도서관

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.