The ultraviolet spectral response characteristics of several 1P28 photomultipliers constructed in quartz envelopes, and of conventional 1P28 photomultipliers in glass were measured using a vacuum grating monochromator equipped with a thermocouple for measuring the absolute energy at the exit slit. The radiation source was a hydrogen discharge tube. The quartz multipliers were found to respond to 1550A and the glass multipliers to 1750A. The limits and response near the limits were determined by the absorption of the respective envelopes. Each type responded to a small extent at wavelengths below the enevlope transmission limits, because of fluorescence of the envelope. The response at 2537A varied over the same range for both types.
L. DUNKELMAN and C. LOCK, "Ultraviolet Spectral Sensitivity Characteristics of Photomultipliers Having Quartz and Glass Envelopes," J. Opt. Soc. Am. 41, 802-803 (1951)