Introduction to infrared thermal imaging security monitoring applications

Part 1: Introduction to the Principles of Infrared Thermal Imaging

Infrared principle

All objects in nature, as long as their temperature is higher than absolute zero (-273°C), can radiate electromagnetic waves. Infrared radiation is the most widespread electromagnetic wave radiation that exists in nature. It is based on the fact that any object will produce it in a normal environment. Its own molecules and atoms move irregularly and continuously radiate thermal infrared energy. The more violent the movement of molecules and atoms, the greater the radiation energy. On the contrary, the smaller the radiation energy.

Principles of infrared thermal imaging

All objects in nature will continue to emit radiation energy as long as their temperature is higher than absolute zero (-273°C).

The thermal imaging system uses an infrared optical system that can transmit infrared radiation to focus the infrared radiation of the scene onto a device that can convert infrared radiation energy into a physical quantity that is easy to measure - an infrared detector. The radiation signal is converted into the corresponding electrical signal, and then amplified and video processed to form a video image that can be observed by the human eye. The infrared thermal imaging system converts the infrared radiation emitted by the object into a thermal image visible to the human eye, thereby extending the human eye's visual range to the invisible infrared region.

The image output by an infrared detector is usually called a "thermal image" because different objects or even different parts of the same object have different radiation capabilities and their reflection of infrared rays. By utilizing the difference in radiation between the object and the background environment and the difference in radiation from each part of the scene itself, the thermal image can present the radiation fluctuations of each part of the scene, thereby showing the characteristics of the scene.

Part 2: The application of infrared thermal imaging cameras in the field of security monitoring

The infrared imaging industry was born out of the security video industry. The basic functions of its products are real-time detection and monitoring of human bodies, objects, etc. However, compared with visible light imaging, infrared imaging is all-weather, has strong penetrating power, and can reflect temperature information, etc. Features. Therefore, infrared imaging has its unique advantages.

The principle of optical imaging used in visible light video security is that photoelectric sensitive elements (CCD, CMOS) show different photosensitive characteristics for various colors of light, allowing photography or filming; the principle of infrared imaging is that objects of different temperatures radiate to the outside world Infrared rays of different wavelengths are detected by infrared sensitive elements (such as infrared focal plane detectors), and the image is finally restored through subsequent circuits (such as image processing circuits).

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