Photoelectric Colorimeter

Klett Manufacturing Company

Photoelectric colorimetry was a hot topic in the mid-1930s when Arnoldus Goudsmit Jr. and William Henry Summerson described a photoelectric colorimeter of their own design. As graduate students at the Cornell University Medical College, Goudsmit and Summerson knew that the "progress of analytical biochemistry in the past 30 years has been closely associated with the use of the colorimeter as a measuring instrument," and they believed that an instrument that used standard photocells to measure the intensity of light would give more reliable results than one that depended on the eyesight of individual people.