1. Visual illuminance meter: it is inconvenient to use, the accuracy is not high, and it is rarely used;
2. Photoelectric illuminance meter: commonly used selenium photovoltaic illuminance meter and silicon photovoltaic illuminance meter Composition and use requirements of photovoltaic illuminance meter:
1. Composition: Microammeter, shift knob, zero point adjustment, binding post, photocell, V(λ) correction filter, etc. Commonly used selenium (Se) photocell or silicon (Si) photocell illuminometer, also known as lux meter
2. Requirements for use:
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 high E, choose 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
③Add a cosine angle compensator (opal white glass or white plastic) 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 (photocell drift changes with temperature)
