Analysis of the working principle of an infrared life detector

An infrared life detector is a high-tech rescue device used to detect signs of life. It has image display and night vision capabilities. It mainly judges different targets by sensing temperature differences. Therefore, it can also work in the dark as usual. It can withstand the harsh conditions of a post-earthquake rescue site, searching for life in smoke, fire, and dark environments. The infrared life detector detects the heat from the victim's body. The optical system focuses the received human body thermal radiation energy on the infrared sensor and converts it into an electrical signal. After processing, the infrared thermal image is displayed by the monitor to help rescuers locate the victims.

Characteristics of the infrared life detector:

1. Night vision

It has night vision capabilities and is not affected by light and ambient temperature. It can work normally without light, helping rescuers quickly and accurately locate victims buried under rubble or hidden behind dust and fog. At the same time, it can withstand the harsh conditions of the rescue site. The infrared life detector itself searches for the presence of life based on the difference between ambient temperature and life temperature. Small temperature difference sensing is approximately 0.08℃.

2. Long-distance detection

Even in the dark, the detection depth can reach tens of meters.

3. Easy to carry

The infrared life detector can be remotely controlled or wired, making it easy to carry and use.

Infrared life detection equipment was initially used in the military field and has been continuously improved with the development of science and technology. The full-function thermal imager launched by the Swedish AGA company in 1988 integrates temperature measurement, modification, analysis, image acquisition, and storage, and uses this technology to develop a portable full-function thermal imager, mainly used for military investigations.

With the development of society, countries have begun to attach importance to the development of technical equipment to reduce casualties caused by various disasters. Infrared detection technology has also shifted from military use to rescue instruments—infrared life detectors.

Infrared life detectors can be specifically used for personnel search and rescue operations, helping rescue team members quickly locate vulnerable lives in or around disaster-stricken areas.

Infrared video life detectors mainly utilize current infrared night vision technology, combined with video display, to provide users with images of objects in invisible areas. Among them, infrared imaging technology is divided into passive infrared imaging technology and active infrared imaging technology. The principle of passive infrared camera technology is that the infrared light emission of any object is higher than absolute zero (-273℃). Because the infrared light emitted by the human body and heating objects is strong, while the red light emitted by other non-heating objects is weak, a special infrared camera can be used to achieve night monitoring. Passive infrared imaging technology has not been used in night vision systems due to its high cost and inability to reflect the surrounding environment.

Active infrared camera technology uses a special "infrared light" to artificially generate infrared radiation, producing infrared light that is invisible to the human eye but can be captured by ordinary cameras. The radiation "illuminates" the scenery and environment, and uses ordinary low-illumination CCD cameras or "infrared low-illumination color cameras" to sense the infrared light reflected by the surrounding environment, achieving night vision capabilities.

Infrared video life detectors mainly use visible or invisible light, which is transmitted to the display screen for imaging via a CCD sensor. With video visualization capabilities, videos can be recorded and saved, and then the internally captured scenes can be analyzed by a computer; this product is intuitive, simple, easy to use, and inexpensive; some video life detectors are also equipped with monitoring heads to detect whether there is sound at the search location, which is more intuitive. Usually, cables are needed to transmit audio signals during use, or cables are used in gaps.