The defination of Distribution Curve Flux and Uniformity ratio of illuminance

- Dec 31, 2019-

Distribution Curve Flux

The unit of the light distribution curve is CD/k.l. m (read: Kendra per thousand lumen). The light distribution curve is the unique property of the lamp. The light distribution curve of the same lamp is exactly the same as that of the same type of electric light source, whether it is 50W, 100W, 500W or 1000W.

With the light distribution curve and the light flux of the bulb, the same method can be used to calculate the intensity of light in any direction and the illumination at a given distance.

From the light distribution curve, we can also see the light distribution properties of lamps, such as casting lamps have symmetrical long and narrow light distribution curve, floodlights have flat light distribution curve, the light distribution curve of asymmetric lamps is asymmetric.


Uniformity ratio of illuminance

Specifies the ratio of minimum illumination to average illumination on a surface. In fixed lighting design, lamps should always be installed at a certain height, and there is a certain distance between each two lamps. When height is certain, the distance between lamps and lanterns is smaller, the uniformity of illuminance is taller, the distance is big, illuminance is not uniform. This uniformity is only related to the ratio of distance to height. For example, some kind of lamps, a design installation height is 10 meters, the distance between the lamp and the lamp is 7 meters; Another kind of design installs when the height is 5 meters, the distance between lamp and lamp is 3.5 meters, these two kinds of installation illuminance difference is very big, but the uniformity of illuminance is same.

The uniformity of the illumination is expressed by the ratio of the minimum illumination to the average illumination in the specified area. Uniformity of illumination is equal to 0.8, which is considered to be the minimum allowable uniformity of illumination.

The distance height ratio of the luminaire is the ratio of the distance between the luminaire with the uniformity of illumination not less than 0.8 and the height of the luminaire.