Intercomparison of luminous flux measurements of high pressure sodium lamps
A set of five carefully manufactured 250 W high pressure Na lamps have been selected as transfer standards and circulated on a radial basis for measurements at 14 different European laboratories. Five 95 V 1000 W tungsten filaments have also been circulated in parallel, in order to distinguish between the basic scales maintained by each laboratory and the measurement problems set by Na lamps. The mean luminous flux differences measured by NPL ranged from +9.8% to -6.1%, the standard deviation being equal to 1.75%. This figure would drop to 0.64% if only eight laboratories were considered. Although, as expected, individual lamps have shown fluctuations in output during use, these mean values have proven to be more than adequate for the task of examining the ability of the participating laboratories to make photometric measurements on this type of Na lamp, and suggest that such lamps might well be used, if required, to provide secondary standards. This document presents the individual reports of the laboratories which participated in the intercomparison campaign. A synthesis report is published full-size with the same title.
Bibliographic Reference: EUR 13916 EN (1991) 284 pp., MF, ECU 12
Record Number: 199111367 / Last updated on: 1994-12-02
Original language: en
Available languages: en