Digital System for Converting Spectrophotometric Data to CIE Coordinates, Dominant Wavelength, and Excitation Purity

A data-gathering system automatically enters spectrophotometric data on paper tape. The data are converted to CIE chromaticity coordinates, dominant wavelength, and excitation purity by a digital computer. The computer uses a weighted-ordinate method for calculating the CIE coordinates, and determines the dominant wavelength and excitation purity associated with these coordinates by a table-searching technique. The system is used for both transmittance and reflectance data.