Traceability and Quality Control in a Radiation Thermometry Laboratory

Abstract

In radiation thermometry, a number of steps have been taken to improve calibration quality at temperatures below 1000 °C. These steps involve work done by national metrology institutes and standards bodies. The Fluke Infrared Calibration Laboratory in American Fork, Utah has benefitted from this progress and has established its own radiation thermometry program. The calibration range of this laboratory is -15 °C to 500 °C. This program involves calibrating radiometric transfer standards (with pyroelectric detectors) that, in turn, are used to calibrate flat-plate radiation sources, sometimes referred to as blackbodies. The transfer standards are calibrated by a sequence of blackbody cavity radiation sources that cover the entire temperature range of the laboratory. The radiometric transfer takes place between the cavity sources and the flat-plate sources. The intended use of the flat-plate sources is infrared thermometer calibration. Both the transfer standard calibrations and the flat-plate calibrations are accredited by the National Voluntary Accreditation Program (NVLAP). This paper discusses the traceability involved in this radiometric calibration program. It also discusses numerous quality control measures that have been taken to improve and assure measurement accuracy for both calibrations.