Addendum: Measurement of emissivity in student laboratories (2020 Eur. J. Phys. 41 015101)

Abstract

Abstract In the preceding paper Ficker (2020 Eur. J. Phys. 41 015101 https://doi.org/10.1088/ 1361-6404/ab4c1e), two alternative methods for measuring emissivity of opaque grey diffuse materials have been presented. In both these methods, the contactless temperature measured by the infrared thermometer has been employed. The thermometer has been set at emissivity ɛ = 1 chosen in the settings menu of the thermometer. This ideal value has been incorporated into the derived relations determining emissivity of material samples. However, no infrared thermometer can work with such an ideal value due to the calibration restrictions during its manufacturing. Thus, a modification of the measured values of contactless temperatures is desirable. The present addendum specifies the corresponding modification of the contactless temperature used in the suggested experimental methods.