How to calculate the US Outdoor Luminaire Classification Types I to IV...
There are in fact 6 types from I to VS/V Q. If the luminaire is not rotationally symmetric (V) or quadrilaterally symmetric (VS/VQ) t hen the following meth od i s used to find out which of I t o IV is the luminaire classification. Classification of Type I to Type IV is based on the extents of isocandle diagrams traced on the surface beneath the luminaire. In fact it just considers only the 50% of maximum isocandle path. Look at the diagram below: Note that I said isocandle and not isolux . So we project the intensities (not the illumination) onto the road surface to make the diagram. The road and sidewalk together are divided into a grid of 16 rectangles based on the multiples of the mounting height (often abbreviated to MH ). A luminaire will have a distribution (Short, Medium, Long or Very Long) and a type (Type I to Type IV). Here are the steps for finding out these distribution and type. Loc...