C miner
Publish: 2021-03-28 10:28:34
1. The most famous coins are bitcoin, Ethereum, Leyte, doggy, Ruitai, Ruibo, Dasch, etc.
2. A:
bitcoin is a kind of credit currency. No matter how exquisite and perfect it is technically designed, if it can't be exchanged with legal tender, it can only be built on castles in the air and has no value at all. On the contrary, it will have a lot of negative effects on finance and economy. That's why China bans all CIO transactions and makes bitcoin withdraw from the Chinese market.
bitcoin is a kind of credit currency. No matter how exquisite and perfect it is technically designed, if it can't be exchanged with legal tender, it can only be built on castles in the air and has no value at all. On the contrary, it will have a lot of negative effects on finance and economy. That's why China bans all CIO transactions and makes bitcoin withdraw from the Chinese market.
3. Selection and installation of surveillance camera:
1. Select according to the installation mode. If it is installed in a fixed way, ordinary or hemispherical surveillance cameras are mostly used. If it is installed in pan tilt, integrated surveillance cameras are mostly used, such as Sanno's sn-220c. Its features are: built-in electric zoom lens, small and beautiful, easy to install, and high cost performance. It can also use ordinary surveillance camera with electric zoom lens, But the price is relatively high, and the installation is not as simple as the integrated surveillance camera
2. Select according to the installation site. Because the ordinary surveillance camera can be installed on both wall and ceiling, it is not limited indoor and outdoor, and it is more flexible. The hemispherical surveillance camera can only be installed on the ceiling, so it is mostly used indoor, and the installation height is limited. However, compared with the traditional camera, it does not need to be equipped with lens, protective cover and bracket. It is easy to install, beautiful and hidden, and the price is economical
3. Select according to the ambient light. If the light condition is not ideal, we should try to choose the monitoring camera with low illumination, such as color super bottom illumination monitoring camera, color black-and-white automatic conversion al-purpose monitoring camera, low illumination black-and-white monitoring camera, etc., in order to achieve better acquisition effect. It should be noted that if the light illumination is not high and the user has high requirements for the clarity of the monitored image, the black-and-white camera should be selected. If there is no light, infrared lamps must be added to provide lighting or surveillance cameras with infrared night vision function must be selected, such as Sanno's sn-350cwh or sn-350cw surveillance camera. Its characteristics are: the surveillance camera itself has a color black-and-white conversion mode, with lens and mounting bracket, unique vacuum packaging design, no need to install a protective cover when it is used indoors, And the appearance is beautiful, good concealment, cost-effective
4. Select according to the requirements of image definition. If the resolution of image quality is required to be higher, the monitoring camera with higher TV line index should be selected. Generally speaking, for color surveillance cameras, 420 and 450TVL (TV line) are medium resolution surveillance cameras, and 470TVL and above are high resolution surveillance cameras. The higher the definition, the higher the price
5. We should also pay attention to some performance indicators in the proct description. Such as signal-to-noise ratio, driving mode of automatic aperture lens, etc. In general, the signal-to-noise ratio index of TV monitoring system should be greater than 48dB, which not only meets the requirements of the instry standard of not less than 38dB, but more importantly, when the environmental illumination is insufficient, the higher the signal-to-noise ratio, the clearer the image of the monitoring camera. Generally, the driving mode of the lens is double driving, so that the automatic aperture lens driven by DC or video can be selected at will
6. In addition, the installation of security surveillance cameras should be more cautious. Operate correctly in strict accordance with proct instructions, such as working temperature, power supply voltage, etc. The temperature index of most surveillance camera manufacturers is - 10 ～ + 50 ℃. If the temperature and humidity of the use area change greatly, special protection should be added. Because the domestic surveillance camera AC voltage range is generally 200 ~ 240V, the anti power supply voltage change ability is weak, when used in the system need to add a regulated power supply.
1. Select according to the installation mode. If it is installed in a fixed way, ordinary or hemispherical surveillance cameras are mostly used. If it is installed in pan tilt, integrated surveillance cameras are mostly used, such as Sanno's sn-220c. Its features are: built-in electric zoom lens, small and beautiful, easy to install, and high cost performance. It can also use ordinary surveillance camera with electric zoom lens, But the price is relatively high, and the installation is not as simple as the integrated surveillance camera
2. Select according to the installation site. Because the ordinary surveillance camera can be installed on both wall and ceiling, it is not limited indoor and outdoor, and it is more flexible. The hemispherical surveillance camera can only be installed on the ceiling, so it is mostly used indoor, and the installation height is limited. However, compared with the traditional camera, it does not need to be equipped with lens, protective cover and bracket. It is easy to install, beautiful and hidden, and the price is economical
3. Select according to the ambient light. If the light condition is not ideal, we should try to choose the monitoring camera with low illumination, such as color super bottom illumination monitoring camera, color black-and-white automatic conversion al-purpose monitoring camera, low illumination black-and-white monitoring camera, etc., in order to achieve better acquisition effect. It should be noted that if the light illumination is not high and the user has high requirements for the clarity of the monitored image, the black-and-white camera should be selected. If there is no light, infrared lamps must be added to provide lighting or surveillance cameras with infrared night vision function must be selected, such as Sanno's sn-350cwh or sn-350cw surveillance camera. Its characteristics are: the surveillance camera itself has a color black-and-white conversion mode, with lens and mounting bracket, unique vacuum packaging design, no need to install a protective cover when it is used indoors, And the appearance is beautiful, good concealment, cost-effective
4. Select according to the requirements of image definition. If the resolution of image quality is required to be higher, the monitoring camera with higher TV line index should be selected. Generally speaking, for color surveillance cameras, 420 and 450TVL (TV line) are medium resolution surveillance cameras, and 470TVL and above are high resolution surveillance cameras. The higher the definition, the higher the price
5. We should also pay attention to some performance indicators in the proct description. Such as signal-to-noise ratio, driving mode of automatic aperture lens, etc. In general, the signal-to-noise ratio index of TV monitoring system should be greater than 48dB, which not only meets the requirements of the instry standard of not less than 38dB, but more importantly, when the environmental illumination is insufficient, the higher the signal-to-noise ratio, the clearer the image of the monitoring camera. Generally, the driving mode of the lens is double driving, so that the automatic aperture lens driven by DC or video can be selected at will
6. In addition, the installation of security surveillance cameras should be more cautious. Operate correctly in strict accordance with proct instructions, such as working temperature, power supply voltage, etc. The temperature index of most surveillance camera manufacturers is - 10 ～ + 50 ℃. If the temperature and humidity of the use area change greatly, special protection should be added. Because the domestic surveillance camera AC voltage range is generally 200 ~ 240V, the anti power supply voltage change ability is weak, when used in the system need to add a regulated power supply.
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