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TitleRealization of a photometric scale based on cryogenic radiometry
Publication TypeJournal Article
Year of Publication1998
AuthorsClare, J.F., and Nield K.M.
Pagination251 - 254
Date Published1998
ISSN00261394 (ISSN)
AbstractA standard of illuminance responsivity has been realized on a set of photopically-corrected detectors. It is based on the use of a cryogenic radiometer for the measurement of radiant power in terms of electrical standards and on a spectral responsivity scale established on silicon photodiodes in a "trap" configuration to evaluate the photopic response of the detectors. The spectral responsivity of the photometers was obtained from the trap detector by comparison using a spectrophotometer beam which underfilled both. The spatial responsivity of the photometers was found to be non-uniform by up to 1% and this is a significant source of uncertainty in the realization. The measurements of aperture area used visual identification of the edges and were corrected for a bias in the visual technique that was demonstrated by checks with a similar-sized ring gauge robust enough for contact measurement.

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