Today, the security awareness of consumers from all walks of life has increased, and China's security industry has ushered in a new development. For security monitoring, just the daytime real-time monitoring can no longer meet people's needs, and all-weather seamless security monitoring system has been favored by more engineering and customers.
Infrared camera five types
After infrared technology was discovered by British astronomer Herschel in 1800, more and more scientists were studying how to apply it in various occasions. The application of active infrared camera technology in security monitoring has been rapid for more than two decades. The development of technology is more mature. Infrared cameras are developing and growing at lightning speed, and the types of products are constantly diversifying, and the application fields are being further expanded. To sum up, there are the following types:
First, the halogen camera infrared camera that has been eliminated: The halogen lamp has very strong luminous power. Of course, the power consumption and heat generation will be relatively large, and the cost is relatively high. Its fatal disadvantage is its bulkiness, insufficient heat dissipation, and very short life span. Generally within a thousand hours, and the red storm phenomenon is particularly serious, it is not suitable for civilian night vision surveillance. Halogen Infrared Cameras have large power and have optical and thermal conversion of filters. Therefore, the problem of heat generation is particularly serious. The maintenance cost is high and the service life is short.
Second, led infrared camera: led infrared light is composed of a certain number of infrared light emitting diodes. Infrared emitting diodes are made of pn junctions with high infrared radiation efficiency (commonly used gallium arsenide), plus a forward bias voltage to inject infrared current into the pn junction to excite infrared light. The spectral power distribution is center wavelength of 830~950nm, half-peak bandwidth. About 40nm or so, it is a narrowband distribution, which is the range that the CCD camera can sense. Led infrared cameras are generally suitable for short-to-medium distances of 10 to 100 meters and have the highest market share. However, there is a problem of non-uniform illumination. They are mainly suitable for use in corridors, halls, warehouses and other interior and exterior buildings, community perimeters, roads, etc. monitor.
Third, led array infrared camera: The core of the array infrared lamp is a light-emitting diode array (LED array), which has the following advantages compared with the traditional LED: 1. The brightness is high, the output of a single LED array is about 1W-30W, and the brightness is about Is a conventional single led output of 5 ~ 15mw dozens of times, so far range; 2, electrical - optical conversion efficiency is high, ordinary infrared led electro-optical conversion efficiency is only about 10%, and ledarray electro-optical conversion efficiency is improved to 25% Left and right; 3, small size, ledarray technology will be highly integrated lighting unit, under the same brightness indicators than the average led infrared light product size is much smaller; 4, long life, ledarray life of 50,000h, much higher than the average life of led . Array infrared lamp products have a clear deficiency, namely "eccentricity." Since the light emitting angle can reach 120-180 degrees, it is necessary to reduce the light transmission angle through the lens to match the camera lens. This inevitably causes a lot of light to deviate from the center of the lens, resulting in poor light transmission efficiency. The application scope of the led array infrared camera is basically the same as that of the led infrared camera, and it is more suitable for short-distance monitoring applications in the interior and exterior of buildings such as halls and warehouses, the perimeter of the community, and roads.
Fourth, dot matrix infrared cameras use dot matrix infrared light sources. The third-generation infrared light-emitting devices used in dot-matrix infrared lamps are based on the second-generation product, led-array, and are also called second-generation led-arrays. Compared with the first generation, the second generation led-array has the biggest advantages of small size, good heat dissipation, low attenuation, long life, and a rated life of 50,000 hours. The dot matrix infrared lamp is also called high-power array infrared. The biggest difference from the low-power array infrared is higher brightness and lower cost, and through the independent lens, the light distribution angle can be arbitrarily adjusted according to the use demand, so that it can be solved simultaneously. The first generation of "flashlight effects" and the second generation of "eccentricity."
Fifth, laser infrared camera: laser infrared camera irradiation distance is generally up to 300 to 5000 meters, due to energy concentration, the angle is not close to the short distance, the current cost is still high. It is more suitable for the monitoring of forest fire prevention, oil fields, railways, water conservancy, scenic spots, military, aquaculture, ports, and security markets. With the further reduction of costs, it has been applied to many areas that require night vision surveillance including the community. . Therefore, infrared cameras need to determine the type of camera according to the specific use environment, especially the night environment.
Infrared camera common technology debugging
First, installation precautions 1, debugging infrared lights must be carried out at night. The infrared beam illumination position is adjusted at night through an imaging device such as a monitor. And can effectively adjust the lens aperture settings.
2, infrared light can not be directly facing the camera, the infrared light seen by the camera is the same as the daylight that humans see, it will make the image appear anti-white phenomenon.
3. The infrared lamp is not necessarily installed in the same position as the camera. If the camera is far away from the illuminated object, consider installing the infrared lamp between the two. The best way to install in the same location is to install the infrared lamp and the camera in an overlapping manner.
4, the installation height of infrared lights should not exceed 4 meters, too high will affect the reflectivity of light. The angle should be the best from the top down angle of 20 degrees, and the elevation angle is too large to reduce the reflectivity.
5, must guarantee the working indicator of the infrared lamp (see the product specification for details), such as the power supply power of the infrared lamp must be higher than the working power of the infrared lamp itself.
6. The user must first read the instruction manual carefully when using the infrared light, especially the precautions for ensuring personal equipment safety. Check whether the supporting aspects mentioned in the previous section meet the requirements. Whether the influencing factors that should be taken into consideration should be taken into consideration, if not meet the requirements, the equipment used can be adjusted in time.
Second, the use of matters needing attention Angle problem: First of all, the use of large-angle infrared light with a small viewing angle of the lens, there is a waste of light. Second, not the infrared light emission point of view, the better the screen effect.
The problem of the amount of light passing: the relative aperture determines the light transmission capability of the lens, and the relative light flux of the lens whose aperture is f1.0 is four times that of the lens of the relative aperture f2.0. The same camera and infrared light are used together with the above two types. Lens, infrared action distance can be doubled. Large-aperture lens in the infrared monitoring, the conventional lens is four to ten times better, it stands to reason that infrared night vision monitoring must be supporting products. But due to high costs, technical difficulties, Most infrared product manufacturers do not have the ability to supply.
Focus shift problem: visible light and infrared light due to different wavelengths, the imaging focus is not on a plane, resulting in clear images under visible light conditions during the day, and blurred under nighttime infrared light conditions, or clear images under nighttime infrared light conditions, daytime visible light conditions Under the image is blurred. It can be solved in three ways. First, the use of automatic focusing integrated camera; Second, the use of special focus does not shift the lens; Third, the use of professional adjustment tools, under the existing lens conditions can also be achieved Does not shift the color problem: all black and white cameras are sensitive to infrared light. Infrared light is a stray light in the visible light conditions for color cameras, will reduce the color camera resolution and color reproduction, color camera filter The film is to prevent infrared rays from participating in imaging. To make the color camera sense infrared light, there are two methods. First, switch the filter and block the infrared light from entering under the visible light condition; remove the filter under the condition of no visible light and let the infrared light. Into, this scheme gets good image quality but high cost and switching machine The structure will lead to a certain failure rate. Second, a specific infrared channel is opened on the filter, allowing the infrared light with the same wavelength as the infrared light to come in. This method does not increase the cost, but the color reproduction is slightly worse.
How far can infrared night vision go? When the technology arrives home, an infrared night vision system over 100 meters is not a problem. When technology arrives at home, it means that infrared light technology, infrared sensor camera technology and infrared sensor lens technology must be mastered at the same time. All three are indispensable. The distance has been more than 500 meters, but the cost is relatively high, and the civilian market is still relatively limited.
Brominated flame retardants (BFRs) are organobromine compounds that have an inhibitory effect on the ignition of combustible organic materials. Of the commercialized chemical flame retardants, the brominated variety are most widely used. They are very effective in plastics and textile applications, e.g. electronics, clothes and furniture. BFRs are commonly used in electronic products as a means of reducing the flammability of the product.
Types of applications
The electronics industry accounts for the greatest consumption of BFRs. In computers, BFRs are used in four main applications: in printed circuit boards, in components such as connectors, in plastic covers, and in cables. BFRs are also used in a multitude of products, including, but not exclusively, plastic covers of television sets, carpets, pillows, paints, upholstery, and domestic kitchen appliances.
Brominated Flame Retardant Compounds
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Decabromodiphenyl oxide(DBDPO)
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1163-19-5
|
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Ethane-1,2-bis(pentabromophenyl)(DBDPE)
|
84852-53-9
|
|
Ethylene bis-tetrabromophthalimide
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32588-76-4/5
|
|
Tetrabromobisphenol A(TBBA)
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79-94-7
|
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Hexabromocyclododecane(HBCD)
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3194-55-6
|
|
Tetradecabromo- diphenoxybenzene
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58965-66-5
|
|
Brominated Polystyrene
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88497-56-7
|
|
Brominated Polystyrene
|
88497-56-7
|
|
Tetrabromophthalate Diol(TBPD)
|
77098-07-8
20566-35-2
|
|
Tetrabromophthalic anhydride(TBPA)
|
632-79-1
|
|
Brominated Epoxy
|
68928-70-1
|
|
Poly pentabromobenzyl acrylate
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59447-57-3
|
|
2,3,4,5,6-Pentabromobenzyl acrylate
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59447-55-1
|
|
Ammonium Bromide
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12124-97-9
|
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2,4,6-Tris(2,4,6-tribromophenoxy)-1,3,5 triazine
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25713-60-4
|
|
Tris(tribromoneopentyl)phosphate(TTBP)
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19186-97-1
|
|
Tribromoneopentyl alcohol(TBNPA)
|
36483-57-5
1522-92-5
|
|
Dibromoneopentyl glycol(DBNPG)
|
3296-90-0
|
|
2,4,6-tribromophenol
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118-79-6
|
|
TetrabromobisphenolA Bis(2,3-dibromopropyl ether)(BDDP)
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21850-44-2
|
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Carbonate Oligomer of Tetrabromobisphenol A (BC-52)
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94334-64-2
|
|
Carbonate Oligomer of Tetrabromobisphenol A (BC-58)
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71342-77-3
|
|
Tetrabromobisphenol A bis(allyl ether) (BE)
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25327-89-3
|
|
Tetrabromophthalate Ester(TBPE)
|
26040-51-7
|
|
Bis(Tribromophenoxy)Ethane (BTBPE)
|
37853-59-1
|
|
Polydibromostyrene
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148993-99-1
|
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1,3,5-Tris(2,3-dibromoisopropyl) isocyanurate(TBC)
|
52434-90-9
|
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Tribromophenyl allyl ether (TPE)
|
3278-89-5
|
Brominated Flame Retardant
Brominated Flame Retardant Chemicals, Brominated Flame Retardant Materials,Decabromodiphenyl Ethane,Substitution Of HBCD,Tetrabromophthalate Diol,
Brominated Polystyrene,Tetrabromobisphenol A
Shandong Novista Chemicals Co.,Ltd (Novista Group) , https://www.novistachem.com