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unified glare rating, UGR

[5.9.11.5.8] A measure of the discomfort produced by a lighting system along a psychometric scale of discomfort.* UGR is used in many parts of the world as an alternative to visual comfort probability (VCP).

* CIE 117-1995, Technical Report: Discomfort Glare In Interior Lighting. Vienna, Austria: International Commission on Illumination; 1995

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