Thermal jacket. Description, properties, examples.

#thermocasing

Almost every specialist involved in technical means of video surveillance has at least once in his life faced the problem of protecting delicate electronics of a video camera from an aggressive external environment.

The existing concept — “the strongest survives” is associated, first of all, with the impact of an unfavorable environment.

Most cameras are produced in non-hermetic housings (and sometimes without a housing at all), and are not protected in any way from the harmful effects of dust, humidity and low temperatures, which is especially important given the specific weather conditions of Russia.

One ​​more purely Russian feature should not be overlooked — the vandalism of some of its citizens.

Indoors, this is usually not a problem: heating, air conditioning, and ventilation systems maintain a more or less favorable microclimate, the cleaning lady wipes the dust, and the presence of security deters vandals.

But let's say you are faced with the task of installing a video camera in extreme outdoor conditions.

Without reliable protection, this expensive miracle of electronic technology is simply money thrown to the wind (literally and figuratively).

This is where protective housings come into play. This product is designed for one single purpose — to protect the television camera from the harmful effects of the environment.

It would seem that there is nothing complicated — take a housing, mount the camera in it and that's it. But everything is not so simple. Let's try, without going into details, to figure out what a housing is.

First, we need to decide what we will protect our camera from, that is, choose the type of housing protection.

The following types of protective housings are usually distinguished:

• decorative;
• dust-proof;
• protected from opening;
• vandal-proof;
• water-proof;
• heat-proof;
• explosion-proof.

Let's take a closer look at them.

A decorative casing allows you to install the camera so that it is not conspicuous and matches the overall interior design.

Most often they are made in the form of hemispheres, in which it is convenient to adjust the camera. Such housings do not allow you to determine the direction of the TV camera's view. There are housings designed for installation in suspended ceilings.

Dust-proof housings.

The name speaks for itself.

These housings are designed to protect cameras from the effects of dust and dirt particles that are constantly in the air. Most often, they are decoratively decorated cases with minimal sealing, providing the required level of protection. Recently, they have become an anachronism and are quite rare.

Often the camera is installed in a public place and must be protected from human interference.

The minimum requirement is to protect against accidental or unprofessional interference. These are thin plastic housings for simple applications, such as in the lobbies of public buildings — where no one will deliberately damage the cameras.

For the operation of video cameras in harsh outdoor conditions, moisture- and heat-protective housings are used, hereinafter referred to as outdoor.

The most important characteristics of outdoor enclosures are the sealing standard and the operating temperature range.

The sealing property of enclosures is classified according to international standards by two-digit numbers: IP XX.

The first digit indicates protection against penetration of foreign objects into the enclosure, the second — protection against moisture penetration.

Below in Table 1 is given the classification of protective properties of casings (values ​​above the fifth level are given, since lower levels of protection in modern casings are practically not implemented)

Table 1.

All outdoor housings that claim to be professional and have their own market share, a priori must provide the IP 66 standard and ensure the operation of TV cameras in the operating temperature range from – 30 to +50° C.

To create their own microclimate, all professional outdoor housings must have a set of accessories:

• thermoelement – ​​to increase the internal temperature;
• thermal relay – to control the internal temperature and control the thermoelement;
• sun visor – to protect from direct sunlight;
• hermetic entries and hermetic gaskets – to ensure tightness.

Under non-standard outdoor conditions, additional accessories may be required – a fan for cooling the chamber; windshield wipers, in case of heavy precipitation.

When choosing a thermal housing, you should take into account the fact that the CCD matrix of the camera emits a large amount of thermal energy during operation, and a minimum power heater is often sufficient to heat a housing with a small internal volume.

You should also pay attention to the number of cable glands. It is important that only one round cable passes through one cable gland.

An important quality of the housing is ensuring the transparency of the glass.

This requires a small, constantly working heater directly on the glass, so that it does not fog up in the summer and does not freeze in the winter.

Similar casings from different manufacturers have similar features: a cylindrical shape, a protective visor, several cable glands, and a standard mount.

Vandal-proof casings

Vandal-proof casings (photo 1) are capable of withstanding a targeted human attack for a significant period of time.

They are large, all-metal boxes with durable glass, securely attached to a wall or ceiling.

They are used at train stations, stadiums, in passages — anywhere where you can expect an attack from vandals.

The casing will last for several minutes until the police squad, called by the video surveillance operator, arrives.

These housings often have heaters and other accessories for installation in unheated rooms, but are not sealed enough for outdoor use. However, outdoors this problem can be solved by simply hanging the camera higher and further away so that it can't be reached.

Photo 1. Vandal-proof housing

There are housings for special applications.

These include explosion-proof housings, but please do not delude yourself, this does not mean that the camera will remain operational after a bomb explodes a meter from the housing.

This term means that the housing can be used in an explosive atmosphere and will not cause an explosion under any circumstances.

What should be taken into account when choosing the optimal housing, besides the type of protection? Do not forget that it must be compatible with the camera in many ways. We will list only the main ones: size, power supply, type of camera mount, type of heating.

Theoretical course completed.

Now let's turn our attention to the modern Russian market.

The choice is not large, but what we have is what we are happy with.

The domestic manufacturer is represented by three companies: «Sarov Innovative Technologies» (Sarov), «KomKom Electronics» (Moscow), metal products plant AOZT «Olevs» (Veliky Novgorod).

«Sarov Innovative Technologies» — trade marks SVS26, SVS26L, LS260.

According to the manufacturer, this product belongs to the “Hi-End” class. One look is enough to understand that the best foreign analogues were taken as a standard when developing these casings. Also, apparently, the emphasis was placed on versatility; the line includes casings for almost any type of video camera.

SVS 26L is a middle-class thermal casing with a 220 V power supply. On board: a powerful heating element, polished glass, extruded aluminum and die casting. The casing design is protected by a patent.

The next model – SVS26 is positioned by the manufacturer as a “plug and play thermal housing (if this expression is appropriate here). Suitable for any type of camera with a lens with a fixed focal length and a universal camera mount, has a powerful heater for particularly harsh climatic conditions. Power supply 220/24 V, built-in transformer and galvanic isolation by power supply.

Undoubtedly, this model of thermal housing stands out from the entire line of presented housings of this class, claiming the optimal price/quality ratio.

Model LS260 — operating temperature -25…+40?C, bimetallic thermostat, built-in power supply 12/24 V, which is very convenient when connecting cameras with 12 V power supply. Simplified design, easy to install, designed for the widest range of users.

 Zavod metalloizdelii AOZT «Olevs» — trade marks K-KT-15-4, K-KT-15-3.

K-KT-15-4 – thermal housing for modular video cameras. The cylindrical shape of the housing ensures stability in strong gusts of wind, protection from snow and icing. Temperature range from -50 to +50?C.

The housing is powered by 12 V. A heating element installed near the glass prevents fogging. Terminal connections ensure quick and easy installation of the housing.

K-KT-15-3 is a universal thermal housing for installing both modular and case-type video cameras. The cylindrical shape of the housing is supplemented with a sun visor.

Temperature range from -50 to +50?C. Power supply of the housing is 12 V.

A sealed terminal box allows you to connect a video camera on site without opening the working volume.

The vertical position of the sealed entries provides maximum protection against water penetration.

The included bracket provides reliable mounting on any surface without the risk of spontaneous fall or violation of the settings specified by the installer.

“KomKom Electronics trademarks GM60, GM100, GM160.

It would seem that what else can be invented to win the hearts of conservative installers? The highlight of GM housings is that each model is designed for a specific type of camera, which means it is optimally suited for it, possessing all the necessary characteristics to ensure reliable operation.

The modular video camera with a built-in lens fits comfortably in the GM60 housing.

This housing was awarded the title of Best Product of the Year at the Security Technologies 2000 exhibition.

The GM100 housing is designed to install a modular video camera with a lens with ARD (automatically adjustable iris). Convenient internal mount facilitates camera adjustment in the housing. The bracket supplied in the kit allows you to install the housing on almost any type of surface and provides convenient aiming of the camera at the object of observation.

The GM160 housing (photo 2) is designed for Watec cameras (or similar in size).

The bodies of all GM housing models are made of high-strength silumin by high-pressure casting using the latest metal processing technologies.

Optical (coated) glass, a reliable internal heating system, including glass coating and seals made of chemically resistant rubber ensure stable operation in difficult climatic conditions with a large amount of precipitation and a temperature range from -60 to +40C.

All GM series housings have an IP66 protection standard, which undoubtedly deserves due attention from both ordinary and professional users of this type of product.

Photo 2. GM160 housing

Of course, this review cannot ignore the models of housings of leading Western manufacturers, whose products have earned well-deserved respect among Russian installers of surveillance systems.

Videotec (Italy) – models HET, HEM, HEP.

Climate housings (photo 3) for any type of video cameras equipped with fixed-focus lenses and zoom lenses. They can be installed both indoors and outdoors. Easy to install, the ability to install a sun visor, adjustable chassis for mounting the camera, modern design.

The housing material is stamped and cast aluminum, not subject to corrosion, epoxy powder coating.

The housing is equipped with neoprene gaskets and provides protection from the destructive effects of external factors (in accordance with the IP65 standard).

The product implements a number of new technical solutions. A dustproof version is possible.

A professional approach to the design of housings, optimization for various weather conditions — all this distinguishes Videotec from other manufacturers.

Photo 3. HET climate housing

GL606, GL607 housings. Manufacturer unknown, place of manufacture — Taiwan.

Being an inexpensive, and therefore quite popular in Russia, alternative to Videotec, these housings have good characteristics.

Model GL606 has a length of 260 mm, which allows it to easily accommodate a box video camera with any lens with ARD. For cameras equipped with a zoom lens, the GL607 model is designed with a length of 320 mm.

Power and heating of both housings 12/24/220 V. Provides ease of mounting the camera inside the housing and installation in general. In short, considering all of the above, we can say that this product has the right to exist and its market share.

In conclusion, I would like to note that when writing this article, the goal was not to cover the entire market of protective covers.

The authors only tried to talk about the most common, in their subjective opinion, models, in order to help the consumer in such a difficult matter as choosing.

Uvarov Viktor Nikolaevich, Streltsov Roman Valerievich