The principle of thermal webcam 

What is thermal webcam? Let's start with thermal radiation.

Thermal radiation refers to the conversion of internal energy caused by the internal thermal movement of an object into the external emission energy of electromagnetic waves. Objects can also accept electromagnetic waves and convert them into heat. For example, when the sun shines, people in the sun feel warm and people in the shade feel cold.

The large energy of electromagnetic wave radiated by thermal radiation is distributed in the frequency range of 0.5-20um. According to the division of electromagnetic spectrum, the infrared band of thermal radiation is invisible to human eyes.

The infrared light sensitive device is used to change the intensity of infrared light into the level change of electrical signal, and then the level signal is converted into numerical value, and the numerical value is processed to output pictures that reflect the temperature. The principle of thermal imaging is similar to that of ordinary visible light cameras, but the difference is that the imaging spectral range is different.

Two functions of thermal webcam is contactless temperature measurement and night vision.