Streetlight LED is primarily used to illuminate roads both in the city and countryside to reduce the accidents and increase the safety. Good visibility under day or night conditions is one of the fundamental requirements. And it can enable motorists to move along roadways in a safe and coordinated manner. Therefore, properly designed and maintained LED area lighting should produce uniform lighting levels.
The industry has identified 5 main types of light distribution patterns: Type I, II, III, IV, or Type V light distribution. Want to know how to choose suitable and correct distribution patterns? Here we would show and describe each type and how it could apply to LED outdoor Areas & Site Lighting
Type I
Shape
Pattern Type I is a two-way lateral distribution having a preferred lateral width of 15 degrees in the cone of maximum candlepower.
Application
This type is generally applicable to a luminaire location near the center of a roadway, where the mounting height is approximately equal to the roadway width.
Type II
Shape
The preferred lateral width of 25 degrees. Therefore, they are generally applicable to luminaires located at or near the side of relatively narrow roadways. In addition, the width of the roadway does not exceed 1.75 times the designed mounting height.
Application
Wide walkways, larger areas usually located near the roadside.
Type III
Shape
The preferred lateral width of 40 degrees. This type has a wider illumination area if you make a direct comparison to type II LED distribution. In addition, it has an asymmetric arrangement as well. The ratio between the width of the illumination area and the height of the pole should be less than 2.75.
Application
To be placed to the side of the area, allowing the light to project outward and fill the area. Throw taller than Type II but the side-to-side throw is shorter.
Type IV
Shape
The same intensity at angles from 90 degrees to 270 degrees. And it has a preferred lateral width of 60 degrees. Intended for side-of-road mounting on wide roadways width does not exceed 3.7 times the mounting height.
Application
Sides of buildings and walls, and the perimeter of parking areas and businesses.
Type V
Shape
Produces a circular 360°distribution that has equal light distribution at all positions. And this distribution has a circular symmetry of foot-candles that is essentially the same at all viewing angles.
Application
Center of roadways, center islands of the parkway, and intersections.
Type VS
Shape
Produces a square 360° distribution that has the same intensity at all angles. And this distribution has a square symmetry of candlepower that is essentially the same at all lateral angles.
Application
Center of roadways, center islands of the parkway, and intersections but under a requirement of a more defined edge.
Post time: Oct-28-2022
