Beckman Quartz Spectrophotometer, ultraviolet DU model, manufactured by National Technical Laboratories, South Pasadena, California, 1941-50. Serial no. D-36383. Marked presumably as part of the Beckman Historical Collection. Beckman Quartz Spectrophotometer, 1941-1950 1941-1950
Beckman DU quartz spectrophotometer, serial number 1651, made by National Technical Laboratories, South Pasadena, California, United States, c.1940s Beckman DU ultraviolet photoelectric spectrophotometer, 1940s. 1935-1945
