Comparative Calibration of Heat Flux Sensors in Two Blackbody Facilities

Published

November 17, 1999

Author(s)

A V. Murthy, Benjamin K. Tsai, Robert D. Saunders

Abstract

This paper presents the results of heat flux sensor calibrations in two blackbody facilities: the 25 mm variable temperature blackbody (VTBB) primary facility and a recently developed 51 mm aperture spherical blackbody (SPBB) facility. Three Schmidt-Boelter gages and a Gardon gage were calibrated with reference to an electrical substitution radiometer in the VTBB. One of the Schmidt-Boelter gates thus calibrated was used as a reference standard to calibrate other gages in the SPBB. comparison of the Schmidt-Boelter gages calibrations in the SPBB and the VTBB agreed within the measurement uncertainties. For the Gardon gage, the measured responsivity in the SPBB showed a gradual decrease with increasing distance from the aperture. When the gage was located close to the aperture, a distance less than the aperture radius, the responsivity in the SPBB agreed with VTBB measurements. At a distance of about three times the aperture radius, the responsivity showed a decrease of about 4 %. This is probably due to higher convection loss from the Gardon gage surface compared to the Schmidt-Boelter sensor.

Citation

Journal of Research (NIST JRES) -

Volume

104 No. 5

NIST Pub Series

Journal of Research (NIST JRES)

Pub Type

NIST Pubs

Keywords

heat flux, irradiance, sensor, transfer calibration

Citation

Murthy, A. , Tsai, B. and Saunders, R. (1999), Comparative Calibration of Heat Flux Sensors in Two Blackbody Facilities, Journal of Research (NIST JRES), National Institute of Standards and Technology, Gaithersburg, MD (Accessed October 22, 2025)