It has long been a dispute between hunters: which is better, a thermal imager or a night vision device( NVD).The first class of devices helps to clearly see living, heated non-living objects at each time of the day, year. In the dark, the chances of headlonging into a branch are increased because the bark is cold. Russian night vision devices, on the contrary, make it possible to notice inanimate objects, for animals there is no sharp contrast with the environment provided by the thermal imager. An enticing prospect arises - to combine the advantages of devices with one. The principle of operation of the night vision device must be supplemented with the option of distinguishing between natural and artificial light.
Thermal Imagers
Infrared Night Vision works with backlighting, thermal imagers are completely passive. They catch radiation emitted by heated bodies. The notorious Arnold Schwarzenegger in the movie Predator-1 used the peculiarity of the device of the hunter people, hiding from the alien's field of vision. The hero smeared with cold silt, was lost among the driftwood. Alien predator revealed himself, for which he was later punished.
The advantages of a thermal imager: the device sees through the smoke screen, fog, when military night-vision devices fail completely. On a relatively gray field, where objects are outlined, extraneous landscapes of heated bodies of animals stand out as a bright spot. The inventors of the Flir Scout thermal imager have patented a special technology of the Predator film, which was called Instalert( English reduction “anxiety of an event”).Hot figures on the screen become red, targets can not be missed.
Optical Amplifier
Advertisers bashfully hold back what will happen if the ambient temperature approaches 35 ºС, it becomes equal to the hotness of a person. A solid red background appears where it is hard to find living objects. Any Chinese night vision device will continue to give a clear picture. There is no Instalert mode, the familiar landscape is clearly drawn. A person accustomed to color highlighting in extreme conditions is powerless to notice the enemy. Carries potential danger to the operator. Given the high cost of devices, I would like to see a more intelligent system on the market that allows you to operate without fail in extreme conditions.
An additional advantage of the thermal imager: the ability to use the housework, detecting the leakage of the energy of a residential house. Insulating activities are much easier to maintain. Appliances are used by builders. Thermal imagers are promoted by calling promising systems for manual night navigation on waterborne, ground transportation. Authors tend to be skeptical about the prospect. Is to provide the device with a special backlight. In this perspective, a car night vision device looks more attractive because it displays objects, regardless of temperature, the presence of the moon in the sky, and stars. If the night, the lights failed, the imager will help out, exactly until the next time.
The device is ideal for:
- detection of stealing people( thieves, ambushes, Gopnik, murderers);
- tracking hidden animals, birds;
- assessment of the situation of the object.
No Pulsar night vision device will allow you to effectively solve the problem, like a thermal imager. In the presence of many heated bodies, the advantages are leveled. A night vision device with a thermal imager has found a variety of applications. The first is good in the city, in a warm climate, the second - in a snowy forest.
Principles of operation of the NVD
Mentioned: both devices receive radiation, in the case of the NVD, the backlight plays a dominant role. This is how the device works. A typical NVD contains the following parts:
- Optical system.
- Amplifiers.
- Image Building Subsystem.
- Path illumination.
The rays enter through a professional eyepiece, and a photoelectrode plate is fixed at the focus of the lens. The amplifying path begins with it, the unit is placed in a pure vacuum, so that air molecules do not interfere with the movement of electrons inside. Of course, the flow continues to deviate by the gravitational field of the Earth, the effect is hardly noticeable throughout the length of the NVD.
So, the light knocks electrons out of a circular photoelectrode plate, carried away by the positive potential of a microchannel amplifier. You should talk about the device separately. Round plate formed by multiple small cells, indistinguishable to the naked eye. Overtaking the cell, the elementary particle knocks out a myriad of electrons, the process grows like an avalanche. On the back side of the plate, in the area of the cell, a swarm of charges moves on to the phosphor screen. Like a TV, only one color - green. The hue is chosen from the condition of maximum sensitivity of the human eye, the minimum stress of the psyche.
The output optical system forms a picture for the eye. In binoculars, the stream splits into both pupils. In many ways, more convenient due to the peculiarities of the human brain. The military often find the use of monoculars. Unit designs are combined with thermal imaging, night sights, which is more convenient during reconnaissance. Buy a night vision device with a multiplicity of more than 1, will cost money. To increase the device does not work, positioned as a tactical advantage in real time.
Note that there is a vacuum inside the amplifier tube, which does not deflect the rectilinear movement of electrons. Otherwise, the picture is not that it will be blurry, it will not work at all. Only the complete absence of air will allow the device to work. It should be clear faced with tube electronic devices. The rectilinear motion is due to the correct potential distribution:
- The potential on the photoelectrode is lower than the amplifying plate. The highest voltage on the phosphor.
A similar principle is used by cathode-ray tubes of old TVs. Household appliances use three colors of phosphor.
The appearance of the first
PNV Despite the statements of Wikipedia that the fascists belong to the championship, the USSR night vision device also produced. The work was carried out before the beginning of the Second World War. Managed to put into use the Morflot direction-finders, sources of infrared radiation, which play the role of navigation lights. The naked eye to notice the presence of infrared beacons powerless, increased at night the secrecy of the movement of troops.
The research institute 801 was engaged in work in the USSR, on the basis of which in 1983 the Orion branch 1100 was established. Since 1991, renamed the SKB TNV.Please note, people were engaged and thermal imagers. Initially, both branches went side by side. They brought far from a complete historical exposition of the formation of the industry, since we do not consider it important to the issue under consideration. The development department of the NVD included:
- Lighting Laboratory.
- Photometric Laboratory.
- Power Supply Division.
- Onboard equipment department.
- Ground Appliances Department.
- Department of Physical Night Vision Basics.
- Navigation Instruments.
- Department of Thermal Imagers.
- Division of Designers.
Were engaged in the structure of searching for new methods of imaging based on invisible sections of the spectrum. The visible part of the electromagnetic oscillations is a small fraction of the global picture of the universe. The fact involved the exploration of Soviet scientists. The first illuminated NVD was created in the early 50s. Of course, the conveyor supplied the defense industry. The children's night vision device was of little interest to anyone.
The ground-to-air and air-to-air missile guidance complexes operate on the principle of direction finding of infrared radiation of an aircraft engine. Regardless of what they intercept, a helicopter, a plane, another rocket.
The first designs are rather cumbersome. What is the power supply voltage of 45 kV.Slowly but surely, it went forward to ergonomization, economization, optimization. The achievements of thermoelectric refrigerators, classified before the 1992 French conference, were useful. A significant shift in the design of night vision devices gave a multi-alkaline cathode. The device had a low dark current, did not require cooling, the properties exceeded oxygen-cesium equivalents by an order of magnitude.
Selection of NVD
Before you choose a night vision device, think about what requirements you must meet. Today you can get a thermal imager for a smaller amount, it can separately serve the builders. Cheap NVD costs 7,000 rubles, the average citizen of the Russian Federation can afford. Expensive models going wild for 200,000 rubles. Among the parameters, sensitivity and resolution are brought to the fore. Values directly affect the detection range of objects.
Do not try to repair the night vision devices with your own hands. Sophisticated electronic devices, in many ways surpassing the complexity of the mixer.
