What is UGR

UGR full name is Unified Glare Rating. It is a psychological parameter that measures the subjective reaction of the uncomfortable feeling of the human eye caused by the light emitted by the lighting device in the visual environment indoor, and can be used as an index of the individual's comfortable feeling in the room in the lighting design. Its value can be calculated with the CIE unified glare value formula according to the prescribed calculation conditions.

The original industrial and civil lighting design standards stipulate that the direct glare of indoor general lighting is limited according to the brightness limit curve. This limitation method is only for the glare of a single lamp, and cannot characterize the total glare effect of all lamps in the room. Therefore, CIE proposed a unified glare rating (UGR) calculation formula on the basis of comprehensive glare calculation formulas in various countries. It is suitable for the general lighting design of simple cube-shaped rooms, in which lamps are arranged evenly and equidistantly and lamps are double or dual configurated. The observation position is generally at the midpoint of the vertical and horizontal walls, and the line of sight is horizontal to the front.

UGR is represented by a number ranging from 10 to 30. The larger the number, the indoor light will make more people feel uncomfortable direct glare. For example, UGR19 means that 65% of the people in the space do not actually feel the glare interference, but the remaining 35% will feel the discomfort caused by the light on the line of sight.

The market often thinks that UGR represents the attributes of lamps, but it is actually a wrong view. UGR can only be obtained by calculation, rather than finding whether there is glare from light distribution files such as IES. This is the calculated result of the relative relationship between the light-emitting surface of the luminaire and the viewing angle, position of the user or observer, and the background environment. In addition, according to the definition of UGR, UGR cannot be used in lamps where 65% or more of the light is indirect light, nor in narrow-angle spotlights or lamps with asymmetric light.

LIGHT VICTOR anti-glare panel light, UGR<19 under condition of “positive space 4H/8H, reflection coefficient floor, wall 50% and ceiling 70%”.