Estimates of the Uncertainty of Radiative Heat Flux Caclulated From Total Heat Flux Measurements

Published

September 1, 2001

Author(s)

Rodney A. Bryant, Erik L. Johnsson, Thomas J. Ohlemiller, C A. Womeldorf

Abstract

As part of an effort to characterize the uncertainties associated with heat flux measurements in a fire environment, an uncertainty analysis example was performed using measurement data from a room corner surface products test that followed the guidelines of ISO 9705. Equations to model the heat transfer at the surface of a Schmidt-Boelter (thermopile) type total heat flux gauge were selected for use to calculate the incident radiative flux from a total heat flux measurement. The effects of the possible heat flux measurement uncertainty sources were evaluated by employing an uncertainty propagation on the resulting equation for incident radiation. For the model equations and the example conditions selected, the free-stream temperature measurement and the heat flux gauge calibration constant were suggested as major uncertainty contributors. The study demonstrates how to systematically identify major sources of uncertainty for the purpose of reducing total uncertainty and therefore enhancing experiment design.

Citation

International Conference on Fire Science and Engineering

Volume

Interflam 2001

Issue

1

Pub Type

Journals

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Keywords

heat flux, heat flux gauge, heat flux measurements, radiative flux, room corner fire test, standard fire test, thermal radiation, uncertainty analysis

Citation

Bryant, R. , Johnsson, E. , Ohlemiller, T. and Womeldorf, C. (2001), Estimates of the Uncertainty of Radiative Heat Flux Caclulated From Total Heat Flux Measurements, International Conference on Fire Science and Engineering, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=861079 (Accessed October 9, 2025)