Absolute Calibration of a Light Detector

Abstract

A method is described for the determination of the absolute spectral sensitivity of a photomultiplier in the wavelength range from 2200 A to cutoff. The standard of radiation is thermal radiation from a tungsten strip lamp and the dispersing instrument is an arrangement of two conventional grating monochromators in tandem. The major portions of the calibration are the determinations of the monochromator transmissions and then of the relative and finally absolute spectral sensitivity of the photomultiplier. As an example of the use of this detector, the determination of the absolute spectral output of two lamps is described.