1 Subject Content and Application Scope
1.1 This Standard specifies the terms , scope and measuring method of colors of light signals of railway.
1.2 This Standard is applicable to such colors as red, yellow, green, blue, bluish white and purple of light signals of railway.
2 Terms and Symbols
2.1 Color expression system: it refers to the system expressing colors with specified symbols according to a series of specifications and definitions, which is also called colormetric system.
2.2 CIE 1931 standard colormetric system: it refers to the colormetric system expressed by the spectral tristimulus values ( ) specified by the CIE in 1931.
2.3 Three primary colors: the specific color adopted in the color matching test is called primary color. Generally, three primary colors are adopted to form the system. Any one of the three primary colors shall not be formed by mixing the other two colors.
2.4 Tristimulus values: it refers to the amount of three reference stimuluses required for to-be-determined light reaching the color matching in the trichromatic system. XYZ are adopted to express the tristimulus values in XYZ color expression system
2.5 Chromaticity coordinate: Ratio of each of the tristimulus values to their sum. In the XYZ color expression system, the chromaticity coordinates x, y, and z may be calculated with the tristimulus values XYZ.
1 Subject Content and Application Scope
2 Terms and Symbols
3 Color Range of Light Signals
4 Measuring Method for Color of Light Signals of Railway
Appendix A Data Sheet Required by Chromaticity Diagram Drawing and Chromaticity Coordinate Calculation
Appendix B Measuring Method Explanation (Additional)
Additional Information
