Comprehensive test specifications have been developed for the Beckman DK spectrophotometers, which may be applied, with appropriate modifications, to other recording photoelectric spectrophotometers.
Average performance of a random sample of DK-2’s as defined by these tests, has been calculated.
LEE CAHN and B. D. HENDERSON, "Performance of the Beckman DK Spectrophotometer," J. Opt. Soc. Am. 48, 380-385 (1958)