What is Glare?
Glare is the sensation produced by bright areas within the visual field, such as lit surfaces, parts of the luminaries, windows an d/or roof lights. Glare shall be limited to avoid errors, fatigue and accidents. Glare can be experienced either as discomfort glare or as disability glare. In interior work places disability glare is not usually a major problem if discomfort glare limits are met.
What is UGR?
UGR is short from Unified Glare Rating.
The rating of discomfort glare caused by directly from the luminaries of an indoor lighting installation shall be determined using the CIE Unified Glare Rating (UGR) tabular method, based on the formula:
The UGR Scale: 10 - 13 - 16 -19 -22 -25 -28
Where high values indicate more discomfort glare and low values indicate low discomfort.
|
UGR |
Discomfort Glare Criterion |
|
10 |
Imperceptible |
|
13 |
Just perceptible |
|
16 |
Perceptible |
|
19 |
Just acceptable |
|
22 |
Unacceptable |
|
25 |
Just uncomfortable |
|
28 |
Uncomfortable |
