Light decay and life measurement estimation method

Update:23 Mar 2019

The illuminance method is used instead of the luminous […]

The illuminance method is used instead of the luminous flux method. The horizontal illuminance value of one point per 1 meter at the center point and the axis along the road direction is measured at a distance of 2 meters from the height of the lamp. A total of 5 points are measured, and compared with the initial values of each point. The average maintenance rate value of 5 points. Between 2000-5000h, the average maintenance rate is measured every 336h; if the luminaire still meets the requirements at 5000h, the illuminance value of each point at 2000h is the initial illuminance value, and the measured illuminance value per 336h interval is At 2000 h, the corresponding initial illuminance values were compared and the average maintenance rate was obtained. The average maintenance rate fit of the above 10 points was used to estimate the life time when the average maintenance rate was 75% plus 5000 h, which is the life of the lamp. One of the street lamps was selected, and the luminous flux at 0-2000 h was measured by the photometric distribution test method, and the lumen maintenance rate of 2000 h was calculated as a calibration value. When measuring illuminance, the ambient temperature should be controlled at 25 ° C ± 1 ° C for more than 3 h.

Maximum temperature: According to the provisions of Chapter 12 of GB7000.1-2007.
Maximum heat sink temperature: Select the highest temperature of the heat sink in the LED, and place the thermocouple on the heat sink closest to the bottom of the LED.
the main light parameters of the lamp:
Average color temperature and average color rendering index
At 25 ° C ± 1 ° C ambient temperature and rated voltage, rated frequency, measured by the integrated spectrum test system, the lamp sample is placed in the integrating sphere, to avoid direct light into the test probe, the outer surface of the lamp should be pasted does not significantly affect the color temperature test White cover film. Test after 1 hour of ignition.
Luminaire efficacy and lighting distribution curve
Measured with a photometric distribution test system at an ambient temperature of 25 °C ± 1 °C. Firstly, the luminous flux and intensity distribution of the luminaire, the light distribution curve, etc. are tested. The luminous efficacy of the luminaire is the ratio of the luminous flux of the LED street lamp to the actual power consumption of the luminaire.
Immunity: According to the method specified in GB17626.5.