Abstract
Deuterium discharge lamps with magnesium fluoride windows sealed to envelopes by means of pure glass-blowing techniques have been developed at NPL as radiance transfer standards between 115 and 370 nm. It is shown how the problems of the complex molecular emission spectrum of deuterium below 165 nm are overcome at the calibration stage provided the bandwidth of the spectroradiometric system to be calibrated is known. Total power dissipation of about 15 W, compact construction, ease of use, high radiance and aging rates less than 0.05% h-1 are some of the advantages discussed.