How Infrared Sensors Work?

一、The working principle of infrared sensors–Introduction

Infrared sensor, is a sensor that uses infrared as the medium to complete the measurement function. It has many advantages such as fast response speed.

二、The working principle of infrared sensors–classification

Infrared sensor is one of the sensors classified according to different principles, and it can be further classified according to different conditions. It can be divided into level type and pulse type according to the driving method of infrared radiation tube; according to the detection principle, it can be divided into photon detector (the detection principle is based on the photoelectric effect) and thermal detector (the detection principle is based on the thermal effect); according to The functions can be divided into five categories: radiometer, search and tracking system, thermal imaging system, infrared ranging communication system and hybrid system.

三、The working principle of infrared sensors–Structure

The basic components of an infrared system and their functions are as follows:

1) The target to be measured: set the infrared system according to its infrared radiation characteristics;

2) Attenuation of the atmosphere: When the infrared radiation of the object to be measured passes through the atmosphere, it will be affected by a variety of substances to cause attenuation;

3) Optical receiver: used to receive part of the infrared radiation and transmit it to the infrared sensor;

4) Radiation modulator: also known as a modulation disc or chopper, used to modulate infrared radiation into a changed form to provide the azimuth information of the object to be measured and filter out interference signals;

5) Infrared detector: It is the core of infrared system, used to detect infrared radiation;

6) Detector refrigerator: used to cool the system to improve work efficiency;

7) Signal processing system: Amplify and filter the signal to extract the required information and transfer the effective information to the display device;

8) display device: is the terminal device of the infrared system, used for the display of effective information.

四、The working principle of infrared sensors

Above we have also described that infrared sensors can be divided into photon detectors and thermal detectors according to the detection principle. Below we take the thermal detector as an example to describe the working principle of the infrared sensor.

The detection principle of the thermal detector is based on the thermal effect. When the object to be measured is radiated, it will cause the temperature to increase, which will affect the performance change of the object. Therefore, radiation can be used to detect the amount of electricity or non-electricity of the object to be detected.