A method for the rapid measurement of reflectance, transmittance, and grating efficiencies in the region 1140A to 1190A is described. The method takes advantage of four narrow atmospheric transmission bands and requires no vacuum or dispersing system. The detector is a recently improved thermoluminescent phosphor which is sensitive only to wavelengths below 1340A. Reflectances obtained from samples of various materials are given, and aging and cleaning of aluminum surfaces are studied. The measured efficiencies of four 15 000 lines-per-in. aluminum gratings ranged from ½ to 5 percent.
J. D. PURCELL, "Reflectance Measurements from 1140A to 1190A by a Simple Open Air Method," J. Opt. Soc. Am. 43, 1166-1169 (1953)