Tritium-activated RGB reference sources for the calibration of CRTs

This paper proposes the use of tritium-activated light sources made up of CRT phosphors to act as transfer devices between reference spectroradiometers and CRT color measuring instruments. We describe the composition and characteristics of these sources and discuss their suitability as standards. We report on the laboratory measurement and testing of sources of similar nature obtained from a safety sign manufacturer. In these experiments we tried to tag red, green and blue sources with precise tristimulus values in order that they could serve as reference targets for the application of matrix correction methods to colorimeters. We find that chromaticity values can indeed be obtained with adequate accuracy. The establishment of reference luminance values was found to be problematic because the set of sources used showed noticeable spatial non-uniformity, a problem that should be overcome by tighter control of the fabrication process and careful sample selection.