What is the working principle of thermal imaging camera in security monitoring?


With the development of thermal imaging technology, infrared thermal imaging cameras have been successfully applied to security monitoring. In some complex surveillance scenarios, it has more obvious advantages than general infrared surveillance equipment. This application uses the infrared thermal imaging camera to search for targets in a large area at a long distance, which greatly meets the long-distance and large-scale monitoring and detection needs of night vision monitoring in the security industry. So, what is the working principle of infrared cameras in security monitoring?

The working principle of an infrared thermal imager is because it does not require the assistance of an external light source, but instead receives infrared radiation generated by the object (related to the temperature of the object itself), that is, to capture the temperature of the object. The object to be imaged. Although infrared radiation (IR) cannot be observed with the naked eye, an infrared thermal imaging camera can convert it into a visible light image, depicting the temperature change of the measured object or scene. Any object with temperature will emit infrared rays. The higher the temperature of the object, the greater the amount of infrared radiation. The thermal imager receives the infrared rays emitted by the object, displays the temperature distribution on the surface of the measured object through color pictures, and finds out the abnormal temperature points according to the subtle temperature difference, thereby playing a role in maintenance. It is also commonly referred to as an infrared camera.


Its core is a thermal imager, which is a sensor that can detect extremely small temperature differences and convert the temperature differences into real-time video images for display. But only the thermal contours of people and objects can be seen, and the true colors of the objects cannot be seen clearly.

The infrared energy emitted by the object is focused on the infrared detector through an optical lens. The detector sends the information to the sensor electronics for image processing. Electronic components convert the data sent by the detector into a viewfinder or standard video surveillance. The image viewed on the monitor or LCD monitor.

Infrared thermal imaging is a technology that can convert infrared images into thermal radiation images, and can read temperature values from the images. Therefore, each pixel in the thermal radiation image is actually a temperature measurement, which can realize the non-contact measurement of the surface temperature of the object.

The structure of an infrared camera is similar to a digital camera. The main components include the lens that directs infrared radiation to the detector, as well as software and electronic equipment for processing and displaying thermal signals and thermal images.

Work criteria

Natural light is composed of light waves of different wavelengths. The visible range of the human eye is approximately 390-780nm. Electromagnetic waves shorter than 390nm and electromagnetic waves longer than 780nm cannot be felt by the human eye. Among them, electromagnetic waves with a wavelength of less than 390nm are outside the violet light in the visible spectrum and are called ultraviolet rays; electromagnetic waves with a wavelength exceeding 780nm are outside the red of the visible light spectrum and are called infrared rays, and their wavelength range is 780nm to 1mm.


Thermal imaging monitoring advantages:

1. Target monitoring at night and under severe weather conditions.

At night, the environment is not illuminated by sunlight, no fingers can be seen, and the dim light of street lights is faintly visible. In addition, many targets are not illuminated by street lights at all, making it difficult to see the targets clearly. If you use an infrared thermal imaging camera, you can overcome the visual difficulties caused by the dark night. The working principle is to automatically receive the infrared heat radiation emitted by the measured target. Especially in bad weather conditions, it can still monitor various targets, personnel, vehicles, etc.

2. Fire monitoring.

The biggest function of the thermal imager is to measure the temperature of the target. Therefore, when a fire alarm occurs, it can quickly find the precise location of the fire by receiving infrared heat radiation. The thermal imaging camera can be worn even in heavy smoke. Through the layers of smoke, the fire point was found and helped to extinguish the fire in time.

3. Identify camouflage and concealed targets.

During the investigation of the case, the police need to track some targets. These fugitives are often hidden in the grass. With the help of visual impairment, it is difficult for people to find them. In this case, an infrared thermal imaging camera can be used. The human body temperature is constant, and the target track is no longer hidden, which greatly reduces the search labor cost and saves the search time.

Making good use of the working principle of thermal imaging cameras will only help the development of security work. Infrared thermal imaging camera has become a good partner for people's security work, because it is like a talking machine, which continuously records target temperature data, generates images for relevant personnel to analyze, and finds the target immediately for accurate monitoring when needed.