Field fence also called Hinge Joint Fence grassland garden mesh(Grassland Fence).
Field Fence is commonly made for hot dip galvanized wire, the rate of zinc is generally 40-50g/m2, wet regions are higher, using around 230g/m2. Some contries like Africa use the elctric galvanized wire instead.
Usully the horizontal wire using steel wire to increase the mesh impact resistance.
Filed fence specification:
1. top and bottom wire diameter: 2.5mm
2. inner wire diameter: 2.0mm
3. the common size: 7/150/813/50, 8/150/813/50, 8/150/902/50, 8/150/1016/50, 8/150/1143/50, 9/150/991/50, 9/150/1245/50, 10/150/1194/50, 10/150/1334/50, 11/150/1422/50 (The first data is the No. of line wire: The second data is horzontal hole size: The third data is the height of field fence: The fourth data is the total length of each roll)
Field fence Farm Fence,Hinge Joint Fence,Galvanized Field Fence,Grassland Fence Anping Deming Metal Net Co.,Ltd , https://www.wovenfence.nl
2, in the power selection must choose the power adapter of well-known manufacturers, it is best to use the product to obtain the national 3C certification, many small workshop products in order to reduce the cost of the majority of the use of refurbished parts production, because many components have reached or near the life The limit, the use time is not long will appear the damage or the power drop phenomenon, also is this kind of power adapter filter and the voltage regulator circuit part is very simple, even does not have, when the mains voltage volatility is bigger, it is difficult to guarantee to the camera etc. to provide the stability With a clean power source, it is easy to burn down the camera and other equipment, greatly increasing the cost of the after-sales service of the engineering company and even affecting the reputation.
3, in the rural environment, please use the switching power supply, the reason is that the rural power supply voltage is low, some areas even less than AC180V, the primary voltage is too low to cause the secondary output is insufficient, the DC output is difficult to protect 12V, and the camera core operating voltage is 12V ±10%. Insufficient supply voltage will cause the camera to freeze (the image will disappear after a long time, the image will be restored after re-plugging the power, the image will disappear after a long time), and the long-term low-voltage operation will burn the camera.
4, centralized power supply, please ensure that the power line of the full diameter, so as to avoid oversize Wire caused by the supply voltage, current shortage (calculation: GB 1 square copper wire can pass up to 3A of current, and a night vision more than 40 meters The power consumption of the camera should be around 1.0A, which will affect the normal operation of the camera.
5, please use the national standard video cable, non-standard cable material is poor (non-oxygen-free copper), will cause increased impedance, attenuate the intensity of the video signal, resulting in image blur; Second, non-standard cable shielding network is mostly not pure Copper material, not easy to solder, but also easy to fall off, prone to failure hazards. In addition, please use the regular manufacturer's national standard BNC connector, must be pure copper material (needle surface gold plated), otherwise it will be due to the lack of flexibility or difficult to solder caused by virtual connection, resulting in unnecessary after-sales service, affect reputation.
6. China has entered a thunderstorm-prone meteorological period. We must fully consider lightning protection during the design of the project. Customers may not adopt it, but we must not say anything to avoid causing disputes afterwards. Even if the customer does not adopt it, after the construction personnel enters the site, they should first measure whether Party A's mains electricity has a good grounding, and whether the polarity of mains power meets the cabling principles of left-right-zero-fire; Ground protection, do not ignore (most of the host panel has reserved the bottom line terminal); Even if the VCR circuit design has a surge-proof design, it must be grounded, otherwise the surge is unfavorable, the same harmful equipment.
7. It is recommended to use better hard disk video recorders and capture cards to ensure video playback. In the selection of video equipment, it is necessary to actively communicate with customers to understand the real needs of customers, so as not to cause trouble due to the customer's expectations during project acceptance. Currently on the market video playback effects are CIF, HalfD1, non-real-time D1, D1 four, CIF effect in the small screen playback when the picture quality is better, the image is enlarged when there are fewer pixels, there will be fuzzy or mosaic phenomenon; HalfD1 is twice The CIF effect is better than the CIF effect when the image is zoomed in; the non-real-time D1 effect ensures a clear picture when playing back, but the image is incoherent; the D1 effect is a four times CIF effect, because the pixel is high in playback no matter whether it is a small picture or a large picture The effect is more ideal, D1 effect is called the primary broadcast effect, the current video recording effect has been developed to the D4 effect above, but the security industry is only designed to D1 effect at this stage. These common sense must be understood to avoid misunderstandings with customers.
8. Comparison of three common compression formats for video recorders and capture cards 
From the above figure, the picture quality of H.264 is the best under the same Bitrate. For example, when Bitrate is 100kbps, H.264 is about 3dB (about 2x) better than MPEG4, and about 10dB better than MJPEG (about 10). Times) In other words, H.264 can store twice as much time as MPEG4 and 10 times more time than MJPEG before storing the same quality and speed. That is, under the same Bitrate, the bandwidth occupied by MPEG4 and MJPEG transmissions is 2 and 10 times that of H and 264, respectively. 
Security Engineering eight basic common sense analysis
1, please use sufficient power. Night vision camera power supply calculation method: how much the first number of infrared lights, such as the KL-5975 series is 45 8mm diameter 16ML high power infrared light, 45 sets of 7 power supply, each group is about 90-100mA power consumption, total The power consumption is about 700mA, plus CCD board 110mA, total about 810mA, the required power is: 810mA*1.3=1053mA, namely 1A. Insufficient power will affect the night vision effect.