SAE J578:2020 pdf free

SAE J578:2020 pdf free.(R) Chromaticity Requirements for Ground Vehicle Lamps and Lighting Equipment
If two or more lighting functions are optically combined, the color requirement of each function shall be met when individually iluminated. In addition, if the functions are iluminated simultaneously, the emitted light shall not be a color other than the colors permitted by the requirements of the iluminated functions.
Some devices may emit a different color of light in one direction than another. Measurements shall be made in as many directions as needed to define the color characteristics of emitted light and to ensure the color requirement of the function is met in all directions.
Some instruments (tristimulus and spectroradiometric) use an integrating sphere at the inlet port of the device to integrate all the light from the device. Care shall be taken to assure that the integrating sphere is not combining different color light emitted in different directions from the device and thereby providing an erroneous reading.
In this method, photoelectric detectors with spectral responses that approximate the 1931 CIE standard spectral tristimulus values are used to make the color measurements. These measured tristimulus values are used to calculate the chromaticity coordinates of the color of emitted light from the device. The instrument used for this type of measurement is a colorimeter.
These instruments are generally used for production control of color and are satisfactory if calibrated against color filters of known chromaticity coordinates. As a rule, the tristimulus method should only be used on incandescent steady-state sources. Other sources must use the method prescribed in 4.1.2.
A change bar (1) located in the left margin is for the convenience of the user in locating areas where technical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only.SAE J578 pdf free download.