Temperature Uncertainties for Bare-Bead and Aspirated Thermocouple Measurements in Fire Environments.
Temperature Uncertainties for Bare-Bead and Aspirated
Thermocouple Measurements in Fire Environments.
Pitts, W. M.; Braun, E.; Peacock, R. D.; Mitler, H. E.;
Johnsson, E. L.; Reneke, P. A.; Blevins, L. G.
Thermal Measurements: The Foundation of Fire Standards.
American Society for Testing and Materials (ASTM).
Proceedings. ASTM STP 1427. December 3, 2001, Dallas,
TX, American Society for Testing and Materials, West
Conshohocken, PA, Gritzo, L. A.; Alvares, N. J.
Editor(s), 3-15 pp, 2003 AND U.S./Japan Government
Cooperative Program on Natural Resources (UJNR). Fire
Research and Safety. 14th Joint Panel Meeting.
Proceedings. May 28-June 3, 1998, Tsukuba, Japan,
240-247 pp, 1998, 2003.
fire research; fire science; fire suppression; aspirated
thermocouples; enclosures; fire tests; measurement
uncertainties; temperature measurements; thermocouples
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.