1. Types of Illuminance Meters
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.
The composition and use requirements of the photocell illuminometer:
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.
② There is a V(λ) correction filter inside, which is suitable for the illumination of light sources with different color temperatures, and the error is small.
③ A cosine angle compensator (opal white glass or white plastic) is added in front of the photocell because the photocell deviates from the cosine rule when the incident angle is large.
④The illuminometer should work at room temperature or close to room temperature (photocell drift changes with temperature).
2. How to use the light meter
①Turn on the power.
②Open the photodetector cover and place the photodetector horizontally in the measurement position.
③Choose the suitable measurement gear.
If only "1" is displayed on the left end of the display, it means that the illumination is excessive, and you need to press the range key (⑧ key) to adjust the measurement multiplier.
④The illuminance meter starts to work and displays the illuminance value on the display screen.
⑤ The data displayed on the display screen changes constantly. When the displayed data is relatively stable, press the HOLD key (⑧ key) to lock the data.
⑥ Read and record the observations displayed in the reader. The observed value is equal to the number displayed in the readout multiplied by the span value.
For example: 500 is displayed on the screen, the display status in the lower right corner is "×2000", and the illuminance measurement value is 1000000lx, ie (500×2000).
⑦Press the lock switch again to cancel the reading lock function.
⑧ During each observation, three consecutive readings are taken and recorded.
⑨ After each measurement is completed, press the power switch key to cut off the power.
⑩ Close the photodetector cover and put it back in the box.
