Uncertainty Evaluation of NIS Low Stirred Liquid Bath Blackbody Radiation Source (LSBB).

In order to increase the calibration capabilities of infrared thermometer, an extension to the non-contact temperature scale has been performed by the National Institute for Standards (NIS) using a LSBB for the low temperature range from − 30.0 to + 30.0 °C. A high emissivity cavity was developed as a temperature source for the infrared thermometers under calibration. A characterization had been performed and included studies of temperature stability, homogeneity, cavity bottom uniformity, efficiency, blackbody emissivity evaluation, determination of the source size, distance effect, the effect of reflected ambient radiation and the cavity bottom heat exchange. This study showed that NIS is capable of calibrating the secondary standards, establishing the metrological tractability and disseminating those calibration services. This calibration service is now accredited from the Egyptian Accreditation Council (EGAC) with uncertainty ranged from 0.4 to 0.5 °C. [ABSTRACT FROM AUTHOR]