The Working Principle and Application of Environment Visibility Sensor

The Environment Visibility Sensor is equipped with stable and efficient light sources such as lasers or LEDs. Taking the infrared LED as an example, it emits infrared light with wavelengths of 940nm, 930nm, or 870nm. After being collimated by a lens, the light is directed towards the atmospheric sampling space. When the light propagates in the atmosphere, it scatters when encountering particles such as dust, haze, and water droplets. The Environment Visibility Sensor focuses on the forward scattered light in a direction approximately the same as the emission direction. The receiver is at a specific angle, such as 33° or 35°, to the transmitter. The photodetector on the receiver is responsible for receiving the scattered light and converting it into an electrical signal. The intensity of the signal is proportional to that of the scattered light. The data processing system of the instrument processes the received electrical signal. Based on the intensity of the scattered light, it calculates the scattering coefficient by using a mathematical model, and then further converts it to obtain the extinction coefficient. By using the relationship between the meteorological optical range (MOR) and the extinction coefficient, the visibility value is finally obtained and presented in the form of numbers or charts for output.

With this series of precise measurement processes, the Environment Visibility Sensor helps us gain an in - depth understanding of the atmospheric visibility conditions.