On-the-Fly Light Measurement of Modulated LEDs with DSP 200
Article by Martin Senft
Instrument Systems addresses increasing demands on light measurement technology in the automotive sector: the goniophotometer AMS 5000 combined with the DSP 200 photometer offers a perfect solution for testing modulated LEDs, which today ensure a driving experience under optimum lighting conditions.
Light measurement, as required for the development and production of modulated LEDs, must satisfy specific requirements. Automotive lighting, for example, has normal modulation frequencies of only a few hundred Hertz. An LED that is dimmed to half brightness is thus switched off for half the time for several milliseconds. If the light source remains stationary, the luminous intensity can be simply determined by the formation of a mean value. However, in order to save measuring time the light distribution is mostly "on-the-fly" scanned in motion. With the goniophotometer AMS 5000 by Instrument Systems the speed of movement can reach up to 50° /s. Thus, there are measuring segments in the range of one tenth of a degree where the LED is not illuminated. Nevertheless the luminous intensity should be determined also at these positions.
published in german language: ELEKTRONIKPRAXIS, LED und OLED-Lichttechnik April 2019
excerpt in english on led-professional.com