Proposed changes to the SI system of photometric units
Open Access
- 1 March 1978
- journal article
- research article
- Published by SAGE Publications in Lighting Research & Technology
- Vol. 10 (1) , 37-40
- https://doi.org/10.1177/096032717801000106
Abstract
It has recently been proposed that the lumen should become the SI base unit for photometry and that it should be defined in terms of the SI unit of power, the watt. The freezing platinum primary standard source would then be replaced by a primary standard detector, for example an absolute radiometer. As a preliminary measure 683 lm/W has been adopted as the conventional value for Km for use in spectroradiometric calculations. The reasoning behind these changes is briefly presented, together with some discussion of the implications.Keywords
This publication has 4 references indexed in Scilit:
- Redefinition of the Candela and the LumenMetrologia, 1975
- Absolute radiometry by means of a black body sourceProceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 1973
- Corrections in Optical Pyrometry and Photometry for the Refractive Index of AirMetrologia, 1972
- An International Comparison of Radiometric ScalesMetrologia, 1968