Radiative Calibration of Heat Flux Sensors at NIST: An Overview

Abstract

Abstract This paper describes the current capabilities and future plans at the National Institute of Standards and Technology (NIST) for radiative calibration of heat flux sensors. Experimental methods using an existing blackbody and high power lasers have been developed to characterize a reference electrical substitution radiometer and heat flux sensors, respectively. Tests carried out on a typical Schmidt-Boelter heat flux sensor showed long term repeatability of calibration within ± 0.4 %. Factors, such as purge gas flow, affecting sensor calibration when using high temperature blackbodies are discussed. To enhance the present capabilities, two additional blackbody setups are planned. These are a high temperature blackbody operating up to 3200 K with the possibility of calibrating sensors at power levels up to 200 kW/m2, and a spherical blackbody with a water-cooled aperture to calibrate sensors in a low convection environment.