A PROCEDURE FOR TESTING THE RADIOMETRIC ACCURACY OF FOURIER-TRANSFORMINFRARED SPECTROMETERS

We present a simple procedure for evaluation of FT-IR radiometric accu racy, which incorporates the use of calibrated standard reference mate rials. It starts with the standard practice for testing the FT-IR perf ormance recommended by ASTM, as well as using a wavelength/wavenumber standard reference material developed at the National Institute and St andards and Technology. Further steps are proposed to test the noise l evel, linearity, and radiometric accuracy. A set of neutral-density fi lters is being developed for testing the radiometric accuracy. The eff ects of instrumental resolution and apodization function on the radiom etric accuracy for absorption band measurements are also addressed.