Application of an electrically calibrated pyroelectric radiometer to broadband radiometric calibration

The Electrically Calibrated Pyroelectric Radiometer (ECPR) has traceability to national standards in the 0.25 2.0 micrometer wave- lengths. Use of this device as a standard receiver is generally with lasers in this wavelength range. Application of the device to broad- band blackbody calibration is an extension of its normal operation. The results indicated that use of the ECPR with a transmissive window degrades performance significantly. It was shown that by applying a black, spectrally absorbing cover over the detector aperture plate, the problem with using transmissive windows could be corrected. The conclusion formed as a result of the data acquired during this investigation was that the ECPR performs with a ±3% calibration uncertainty in the broadband application (1 to 22 µm). This level of performance uncertainty is comparable to that for other instruments which are also available for broadband radiometric calibration at ambient conditions.