When colorimetric specifications of a large number of samples need be computed from spectrophotometric data, an important saving of time can be realized by use of standard IBM punched-card computing equipment. The method employs weighted ordinates, and results for two light sources can be obtained with very little more expenditure of time than for one. The method is described, with detailed instructions for the machine operators.
DAVID L. MACADAM, "Method of Colorimetric Integration Using Punched-Card Accounting Machines," J. Opt. Soc. Am. 40, 138-138 (1950)