Glare (Unified Glare Rating/UGR)
Glare measurement are used if a more intense source of light dazzles the viewer’s eye. It is split into three different level Discomfort Glare (it is uncomfortable to look at, user wish to look away) Disability Glare (it distracting and causes the user to unable to perform their task) Blinding Glare (causes user to lose vision for a certain period of time). The industrial common uses UGR as a unit of measure of glare. However, a lamp can have a range of UGR as UGR is difference as the distance and viewing angle of users changes, i.e. Glare level is different when you are looking directly at the light or 10 degrees away from the light. Some light distribution reduce direct glare, but have a higher glare when not looking directly at it.
BUG rating -
B-Backlight U-Uplight G-Glare
This is a measure of how well the performs according to international standard. Each type of project (and region) will have different requirement on BUG. According to the different luminance certain directions. Measurements of the lumen at different sector of lamp light distribution is taken and refer against BUG take to provide a rating give in the level of 0-5.