Filter radiometers are being widely used to determine spectral emission scales, photometric scales and for radiation thermometry. The accuracy of the final scales is largely dependent on the accuracy of the calibration of the spectral response of the filter radiometer. There are a number of techniques currently being used to determine the spectral response of the filter radiometer with varying levels of accuracy and complexity. This project aims to compare the accuracy of the different techniques.
An intercomparison is proposed.
A group of filter radiometers of the same basic design but suitable for calibration for spectral responsivity by the different methods. The filter radiometers would have wide and narrow spectral bandwidths to ensure that the methods are assessed for all types of application.
After calibration by participating institutes, a measurement will be made by NPL of the spectral radiance from a fixed point black body, at the copper point, using the same geometric conditions for each radiometer to reduce systematic errors and a comparison made of the results.
The results of the comparison would then be published in Metrologia.
Progress report submitted in May 2004.