Determination of light distance [in metres, m]:
To determine the light distance of a lamp, we find the distance to the lamp where the illuminance measured in the center of the beam equals 0,25 lux.
Determination of light duration [in hours, h]:
To determine the light duration of a lamp, we measure the time after which the illuminance in the center of the beam in 2 metres distance reaches 0,25 lux.
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22.05.2012, 10:30
