Traceability of a CCD-Camera System for High-Temperature Measurements

Abstract

A CCD camera, which has been specially equipped with narrow-band interference filters in the visible spectral range for temperature measurements above 1200 K, was characterized with respect to its temperature response traceable to ITS-90 and with respect to absolute spectral radiance responsivity. The calibration traceable to ITS-90 was performed at a high-temperature blackbody source using a radiation thermometer as a transfer standard. Use of Planck’s law and the absolute spectral radiance responsivity of the camera system allows the determination of the thermodynamic temperature. For the determination of the absolute spectral radiance responsivity, a monochromator-based setup with a supercontinuum white-light laser source was developed. The CCD-camera system was characterized with respect to the dark-signal-non-uniformity, the photo-response-non-uniformity, the non-linearity, and the size-of-source effect. The influence of these parameters on the calibration and measurement was evaluated and is considered for the uncertainty budget. The results of the two different calibration schemes for the investigated temperature range from 1200 K to 1800 K are in good agreement considering the expanded uncertainty $$(k= 2)$$ . The uncertainty for the absolute spectral responsivity of the camera is 0.56 % $$(k= 2)$$ .