Temperature Uncertainties for Bare-Bead and Aspirated Thermocouple Measurements in Fire Environments
William M. Pitts, E Braun, Richard D. Peacock, Henri E. Mitler, Erik L. Johnsson, Paul A. Reneke, L G. Blevins
Temperature measurements have been made for natural-gas and heptane fires in a reduced-scale enclosure using a variety of bare-bead and aspirated thermocouples in order to characterize the uncertainties. The focus is the role of radiative heat transfer and the effects of finite time response on the measurements. The findings show that significant errors are possible for all thermocouples considered. Aspirated thermocouples reduce, but do not eliminate, such uncertainties. An alternate approach, use of several bare-bead thermocouples with extrapolation to zero diameter, is not easily implemented in the time-varying temperature environments characteristic of fires.
American Society for Testing and Materials (ASTM)
December 3, 2001
Thermal Measurements: The Foundation of Fire Standards
, Braun, E.
, Peacock, R.
, Mitler, H.
, Johnsson, E.
, Reneke, P.
and Blevins, L.
Temperature Uncertainties for Bare-Bead and Aspirated Thermocouple Measurements in Fire Environments, American Society for Testing and Materials (ASTM), -1, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=911800
(Accessed December 10, 2023)