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Comparative Calibration of Heat Flux Sensors in Two Blackbody Facilities



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


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.
Journal of Research (NIST JRES) -
104 No. 5


heat flux, irradiance, sensor, transfer calibration


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 June 25, 2024)


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Created November 16, 1999, Updated October 12, 2021