DEVELOPMENT OF IMPROVED ELECTRICAL-SUBSTITUTION RADIOMETERS AT THE NATIONAL-RESEARCH-COUNCIL-OF-CANADA

We describe the development of a third generation of electrical-substi tution radiometers (ESR's) at the National Research Council of Canada. The new ESR's follow the same general design as before, but incorpora te improved thermopiles and electrical heating elements. The ESR's hav e a responsivity between 0.6 and 1.0 VW-1, a time constant of approxim ately 2.0 s, a uniformity of 0.1% over a 6-mm-diameter region, and a n oise level of approximately 6 nW. Performance characteristics of the n ew ESR's are discussed. It is shown that calibrations performed with t hese ESR's agree with those made with the previous generation of ESR's to better than 0.05%. (C) 1996 Optical Society of America