Colorimeter - chromaticity
DEFINITION
A tool for measuring or determining color or chromaticity by comparing with synthesized color. "The typical colorimeter has a built-in standard light source, three colored filters, photoelectric cells or phototubes, a standard reflecting surface, and in modern types, photoelectric cells and electronic circuits to replace the human eye as the receptor and thus speed up results." Source: Ralph Mayer, "A Dictionary of Art Terms and Techniques"