From the point of view is not very inquisitive user imagers are a form of night vision — night vision devices. From the point of view of technology used in them — this is an alternative, a fundamentally different way of solving the problem.
Thermal, if formulated very briefly and primitively, allow you to see not reflected as «traditional» night vision and infrared own facilities. Modern thermal imaging devices can detect human, animal, or running technique in the dense bush, under cover of disguise, or even in complete darkness inside the protected object. Moreover, they can even see the fresh tracks of people, or cars, or disturbed soil.
Arranged imager, contrary to expectations, is relatively simple: a special lens, thermal imaging matrix and an electronic signal processing unit.
The most expensive item is a special lens. The fact that it can not make a conventional glass, because glass does not transmit infrared radiation to that portion of the spectrum where the imager works. For the manufacture of lenses used rare and expensive material — germanium. The cost of a lens made of it, is about half the cost of the entire device. That it does not allow hope for cheaper thermal soon. Actively search for a replacement to this material, but so far the prospects are dim. The second order, but not least, in the thermal imager is a matrix. That it makes it possible to see the invisible thermal radiation. Without going into details, let’s say that each element of the matrix (pixel) is composed of a single thermistor. When it is heated inside the thermistor resistance changes, which is recorded «brain» of the matrix and is translated into a visible image. Thermal imaging matrix can not boast higher resolution, the best of them now have a resolution of 640×480 pixels, is 1.5-2 times worse than the PNV second and third generation, and is ten times worse than any unpretentious camera. For comparison, 640×480 — is 0.3 megapixels, which is a long time past stage, even for the camera built into a mobile phone.
Modern thermal imagers are divided into two main classes. The first — the thermal imager with a cooled matrix using cryogenic coolers, capable of deep-cooled matrix. This makes it possible to make highly sensitive devices with higher resolution. Disadvantages of these devices — a lot of weight over 30 kg — a huge price in the tens and even hundreds of thousands of dollars and a small share of the cooling system (thousands of hours). Typically, these devices are used or installed permanently on the technique.
The second class — devices with uncooled matrix. They are much cheaper, can be made in the form of compact lightweight instruments. Today, therefore, devices of this type occupy more than 90% market share of thermal imagers. Besides uncooled thermal imagers have much more resources and start working immediately after switching.
Thermal found today very widely used in medicine, control of the state of communications, buildings, pipelines, and in the whole heap of other «civilian» tasks, but the main «users» are still the army and security services (primarily, of course, in the US, where these devices most widely), which imposes certain restrictions on the use of not only (hunting rules simply do not have time for technological progress, and therefore did not speak about the imagers) as the import-export.
As can be seen from the properties of thermal imaging, their use in hunting can be very diverse. They can be used not only at night but also in conditions with restricted visibility, for example during fog. It is obvious that such a device will be very useful when searching for wounded game and trophies.
For hunters, certainly interesting are the devices of the second class. They are more compact and, more importantly, work much longer.
On all this wonderful ointment is and fly in the ointment is quite tangible. The fact that the imager is very complex and dependent on external conditions of the instrument. Prior to use, especially in different weather and climatic conditions, it is rather complicated and requires precise adjustment, or the image quality is not important.
Unfortunately, the main cause of the prevalence of low thermal is still the price. Now there is hardly any suitable for hunting purposes imager with a price of less than $ 3-5 thousand., And good equipment until prices fall below $ 10 thousand. This fact severely limits the spread of these devices. Another negative — still a manufacturer offers us to observe monoculars, binoculars and cameras and in a very limited number of sights. So far, the only supplier of Thermal Imaging sights are the United States, by the way, that the removal of the sights of the United States officially closed and all appear in our market instruments, in fact, are smuggled. We note also that the responsibility for violation of this law is quite high — up to 10 years in prison. All of this explains the very high mark-up on these very expensive sights.
Already, you can find several models of Thermal Imaging sights «conditionally available» in our market, for example ThermoSight 50 CCIR, MW 5000 or CS 6000, priced from $ 35 to $ 50 thousand. US.
At the end I would like to mention the devices to search for wounded game and trophies, which are also referred to as thermal imaging, although it would be better to call them teplodetektorami because these devices do not show anything, they do not have a screen and are only able to give signals about Catch the difference in temperature. They represent a small object, like a flashlight, equipped with several diodes. The device is able to capture the increased temperature of the object. The idea is that when you send it to warm object, depending on the temperature difference, illuminate one or more diodes — indicators. With this information, according to the authors, the hunter can determine the direction and approximate distance to the object of the search.
Alexander Kudryashov28 November 2014 at 00:00