Infrared night vision device principle and purchase points
Principle of infrared night vision device
There are not only so many wavelengths of light that our eyes can see. Besides these, there are many other waves that are all around us. It's just that we can't find it with our own senses. Infrared light is the light emitted by objects that exceeds the wavelength of the red color spectrum. Almost all objects will have infrared light, that is, thermal radiation, even the vast space. Radiation exists. Since everything in the world has thermal radiation. Then we can use this commonality to observe objects according to different object temperatures. Ordinary people’s eyes cannot sense infrared rays, so people cannot see things without reflected light in the dark, and any temperature is higher than absolute zero. All objects radiate infrared light, including your body. Therefore, a device that can sense infrared rays is used to detect infrared rays, and then the analog signal is subjected to image processing methods such as background noise removal, amplification, and filtering to restore the outline of the detected object. But color is difficult to reproduce, so images seen by infrared are rarely in color.
When purchasing night vision devices, generally choose according to the following order:
1. To determine how many generations the image enhancing tube is. Because the packaging and manuals of night vision devices generally do not indicate which generations of image-increasing tubes are used. Of course, if you want to buy a 2nd or 3rd generation night vision device, it is best to buy a night vision device that is clearly marked with several generations of image enhancer tubes, so as not to infringe on your rights and interests. Currently on the market, such as the night vision device of Russia RHO, it is marked on the product packaging and the machine which generation of image intensifier tube is used.
2. Look at the lens aperture and magnification lens. Without considering the size, of course, the bigger the better. In the same case of the image intensifying tube, the principle is that the larger the aperture, the farther the observation distance is, and the clearer the image will be.
3. Whether it has image enhancement technology: Generally, the night vision device with this technology will have better image brightness and clearer under the same conditions.
4. The performance of the infrared emitter: the quality of this performance also directly affects the image quality.
5. How about the lens: The resolution of the lens is very important, the higher the resolution, the clearer the displayed image.
As for the nominal observation distance of the night vision device, the identification distance. Since there is no formal standard, different opinions vary. In fact, there is no reference significance. Generally speaking: the distance of the first generation is 100-250 meters, the distance of the second generation is 200-350 meters, and the distance of the third generation is 300-500 meters, which can see objects clearly. It is determined by the quality of the lens, image processing technology, infrared emitter, and resolution.
