A tristimulus photoelectric colorimeter enabling measurements to be made in terms of Munsell color space is described. The instrument has been designed to read approximate hue, value, and chroma directly upon three potentiometer dials. To accomplish this, readings of Adams a and b are obtained and converted into polar coordinates by the instrument after transformation into a uniform color space. The new color space is described. Results on actual renotated Munsell papers are discussed, and it is shown that specimens and standard must be similar in hue, value, and chroma as well as spectral characteristics for satisfactory results.
GILBERT L. GIBSON and DAVID A. NEUBRECH, "Automatic Photoelectric Colorimeter for Direct Reading of Munsell Coordinates," J. Opt. Soc. Am. 44, 703-709 (1954)