I am a Medical laboratory technologist from Sri Lanka. When I used my carrier in 1983 I used Klett-Summerson colorimeter as the start of biochemistry, which was very simple and durable.

The report describes a photoelectric tristmulus spot colorimeter which measures the three stimuli X, Y, Z as specified by the C.I.E. (Commission Internationale de I'Eclairage) standard observer ...

This example is marked "DAVIS-BRUNING COLORIMETER FISHER SCIENTIFIC SERIAL No. 123 Pat 1951 MADE IN U.S.A.” and “115 VOLT 60 CYCLE." The Department of Chemistry of the Rensselaer Polytechnic Institute ...

Summerson, "A Simplified Test-Tube Photoelectric Colorimeter, and the Use of the Photoelectric Colorimeter in Colorimetric Analysis," Journal of Biological Chemistry 130 (1939): 149-166. Location ...