Application and Working Principle of Illuminance Sensor

Illuminance sensor is a common detection device, which has been used in many industries. In many places we will see the light control switch this device, such as street lights, various automated weather stations and agricultural greenhouses inside, but when we see this box with a small ball, we know that this is the illuminance sensor, but for it is still not very well understood, today we come to understand the illuminance sensor.

1. Working Principle of Illuminance Sensor
Illuminance sensors use the hot spot effect principle, most notably the use of detection components with high response to low lightness, these sensing elements are actually like the camera's light-sensitive matrix - like the internal wire-wound electroplated multi-contact thermopile, the surface of which is coated with a high absorption rate of black coating, the hot contact on the sensing surface, while the cold junction is located in the body, the hot and cold contacts produce a temperature difference potential. The output signal is proportional to the solar radiance in the linear range. The visible light through the filter is directed to the imported photodiode, which is converted into an electrical signal according to the magnitude of the visible illumination, and then the electrical signal will enter the processor system of the sensor to output the binary signal that needs to be obtained.

Of course, there are many kinds of illuminance sensors, and some of them are even optimized for the structure described above. In particular, in order to reduce the influence of temperature, illuminance sensors also apply temperature compensation lines, which largely improves the sensitivity and detection capability of illuminance sensors.

2.How to use the illuminance sensor
The illuminance sensor should be installed in an open space around and without any obstacle above the sensing surface. Adjust the sensor to a good horizontal position, and then fix it firmly. It is better to fix the sensor firmly on the mounting bracket to reduce breakage or intermittent interruption on windy days.

Wall-mounted illuminance sensor installation method:First drill holes in the wall, then put the expansion plug into the hole and screw the self-tapping screws into the expansion plug.
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