An example run of the home built Goniophotometer used at [ Ссылка ] to measure the total output and light distribution of LED lights.

Values for the luminous flux of each LED product are obtained by measuring luminous intensity distribution using a goniophotometer. The goniophotometer is comprised of a Extech HD450 Data Logging photometer mounted on a motor-driven arm that rotates in plane and at a fixed distance relative to the light source being tested. Lux (lm/m²) values at each angular step are logged into our custom application in synchronization with the stepper motor actuation. The scanning resolution of our test setup is a 1.8° step. Two axis are measured, (but only one is shown in the video). To avoid ambient light and temperature variation effecting the results, the test was conducted in a dark and temperature controlled room.

The goniophotometer thus allows us to measure the light output of an LED along a circumferential area on two transverse planes. A process of interpolation and integration based on our measurements is calculated, from which the total light output over a spherical surface area, independent of measuring distance, i.e. the luminous flux is obtained.

In reality the movement of the arm is much slower than in the video, which has been sped up 256 times..

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