The ALFI can also measure the luminous intensity distribution, or beam characteristics, of small lamps, LED clusters and luminaires.
The test item is placed on a rotating holder at the centre of the ALFI. A photocell is mounted on an arm that rotates about the test item. As the photocell moves around the test item and the test item itself rotates, the luminous flux is summed over the whole sphere around the test item.
The ALFI comes in two main sizes: the ALFI-1.0 which has a test distance of 1.00 metres and which will fit into a standard room height; and the ALSI-2.0 which is double the size and requires a larger, specialised room.
Because of the small test distance and the sensitivity of the detector, this device is ideal for measuring the luminous flux and luminous efficacy (efficiency) of LEDs and LED clusters.
The ALFI is calibrated absolutely, and it can therefore be used to create reference lamps and to calibrate mirror goniophotometers and integrating spheres.