The IES light distribution curve test refers to the light intensity distribution of the light source (or lamp) in all directions of space. The curve formed by marking the luminous intensity values in all directions on the polar chart is the light distribution curve of the lamp.

The main test parameters include electrical parameters: voltage, frequency, current, power and power factor. Light parameters: luminous flux, luminous effect, central light intensity; Beam angle, ring band luminous flux, color space distribution uniformity.