OPTICAL RADIATION MEASUREMENTS AT CNAM-INM

Résumé

The Institut National de Métrologie du Conservatoire National des Arts et Métiers (CNAM - INM), is the French national metrological laboratory in charge of realising the radiometric and photometric units. Cryogenic radiometers are recognised as the most accurate radiometric standards. Like most of the national standard laboratories world-wide, the CNAM-INM employs such an instrument as the basis for its optical radiation measurement scales. The photometric measurements are used to quantify the visual effect of radiation on the human eye. But, as eye is a very complicated organ and not the same for everybody, it is necessary to define a standard observer which is mainly described by the luminous efficiency function V(λ). The two major photometric quantities for which our laboratory is realising standards are the luminous intensity and the luminous. In this paper is presented a review of the realisation of the luminous intensity unit.