Preventing industrial smoke pollution is one of the important tasks of environmental protection. In order to remove industrial smoke and dust pollution, we must first understand the smoke and dust emissions, so the source of the smoke and dust must be monitored, automatically displayed and alarmed for exceeding the standard. The turbidity of smoke in the flue is measured by the amount of change in light as it travels in the flue. If the flue turbidity increases, due to the absorption and refraction of soot particles, the light emitted by the light source increases, and the light reaching the photodetector decreases. Therefore, the intensity of the output signal of the photodetector can reflect the change of flue turbidity.

The smoke alarm also uses a photoelectric sensor as the core component, which can be used to measure the concentration of smoke. It consists of an infrared light-emitting diode and a phototransistor, but the two are not on the same plane (with an angle). In the smokeless state, the phototransistor does not receive infrared rays. When smoke enters the sensor room, the smoke particles will scatter part of the light beam onto the phototransistor. As the smoke concentration gradually increases, more light beams will scatter onto the sensor. When the beam reaches the sensor, the buzzer sends out an alarm signal.

The above is the application of photoelectric sensor in smoke and dust turbidity monitoring, I hope it will be helpful to everyone.