Types involved:
Visual illuminance meter: inconvenient to use, not very accurate, rarely used
Photoelectric illuminance meter: commonly used selenium photovoltaic illuminance meter and silicon photovoltaic illuminance meter
The composition and use requirements of the photocell illuminometer:
【Composition】: Microammeter, shift knob, zero adjustment, terminal, photocell, V(λ) correction filter, etc.
Commonly used selenium (Se) photocell or silicon (Si) photocell illuminometer, also known as lux meter
[Requirements for use]: The illuminometer probe is made of glass, which is easy to be broken and damaged, and the waterproof effect is very poor when used.
① Photocells use selenium (Se) photocells or silicon (Si) photocells with good linearity; they can maintain good stability after long-term operation, and have high sensitivity; when E is high, use high internal resistance photocells, which have low sensitivity and good linearity , not easily damaged by strong light exposure
②There is a V(λ) correction filter inside, which is suitable for the illumination of different color temperature light sources, and the error is small
③ A cosine angle compensator (opal white glass or white plastic) is added in front of the photocell because when the incident angle is large, the photocell deviates from the cosine law
④The illuminometer should work at room temperature or close to room temperature (the drift of the photocell changes with the change of temperature).
