A comparison of the performance of infrared detectors for radiometric applications.

NPL, the UK National Standards laboratory, is currently engaged in a programme of work to improve the accuracy of measurements in the infrared region of the spectrum (1 to 20 mu m) particularly in the atmospheric windows, with a target best uncertainty of around 0.1%. This work includes the identification of the most appropriate detector type on which to maintain and disseminate the new scale. Transfer standard detectors should ideally be large in area (up to 10 mm diameter), spatially uniform, linear, have high D* values over a wide spectral range and have goad stability/ageing characteristics. A number of detector technologies have been investigated and the characteristics of these devices are described together with an assessment of their suitability as transfer standards.