12.1.2.3-14 Color Rendering

The lighting system should have good color rendering capability. Surface colors, as well as colors on visual display devices, should be recognizable under both normal and emergency lighting conditions. Additional Information: Colored ambient illumination should not be employed if color coding is used in the workplace, since such illumination can interfere with color coding. Some types of lamps

(e.g., mercury or sodium lamps) have very poor color rendering properties. These types of lamps should not be used for normal or emergency lighting if the ability to distinguish among colors may be important. The color rendering index (CRI) is a method of measuring and specifying the color rendering properties of light sources based on the resultant color shifts of test objects. This method employs a set of test-color samples specified by their spectral radiance characteristics. The CRI is determined from the measured color shifts of these samples relative to the colors rendered by an ideal black body radiator light source, in this case, the D series of illuminants constructed to represent natural daylight. In general, the lighting system should achieve a minimum CRI of 80 or more. Methods to calculate and evaluate the CRI may be found in CIE 13.3 (1995). 28 0700, 5680, 5908, 11064-6

 

© ISO. This material is excerpted from ISO 11064-6: 2005 with permission of ANSI on behalf of ISO. All rights reserved.