1. Because the connection between the monitoring system equipment involves many lines, if the processing is not good, especially if the line connected to the main equipment is improperly connected or connected incorrectly, there will be disconnection, short circuit, poor insulation between lines, miswiring, etc. Causes the performance of the device to be reduced or even damaged. In this case, cool analysis and troubleshooting should be performed according to the fault phenomenon to determine what kind of fault phenomenon may occur when there is a problem with the line connection. In addition, it should be noted that the connections between the various system devices and the various lines should meet the requirements for long-term operation of the monitoring system.
2. The mismatch of the characteristic impedance of the transmission cable may cause some vertical bars with equal spacing on the monitor screen, and the frequency of the interference signal is basically an integral multiple of the line frequency. This interference phenomenon is caused by the fact that the characteristic impedance and distribution parameters of the video cable do not meet the requirements. For such interference, the impedance of each device in the system should be matched as much as possible. Especially when the video cable is purchased, the cable quality must be ensured. If necessary, the cable should be sampled and tested.
3, the communication interface or communication protocol and other parameters are not set well, this situation often occurs between the control host and decoder or control keyboard and other devices with communication control relationship. In other words, the selected control host and decoder or control keyboard, etc., are not set during the installation of the communication protocol and other parameters, so the host, decoder, control keyboard, etc. should pay attention to the communication protocol and other parameters during installation Settings.
4. Common faults of video interference.
• A black bar or white bar appears on the monitor screen and scrolls up or down, which is the so-called 50 Hz power frequency interference. This kind of interference is caused by the potential difference loop caused by the improper grounding of the two devices at the front end and the control center. It may also be caused by the degradation of the power supply performance of the device itself.
Image has snowflake noise. This type of interference is mainly caused by signal attenuation on the transmission line and coupling of high-frequency interference. The video image has ghosting, or the image is whitish, the character is jittery, or there are several pitches on the monitor screen. Equal vertical bars interfere. This is because the characteristic impedance between the video transmission line or the equipment is not 75Ω, resulting in impedance mismatch;
Twill interference, jitter, power interference. When this interference is slight, it does not overwhelm the normal image, but when it is severe, the image is distorted and cannot be viewed. The reasons for this are more and more complicated. For example, the quality of the video transmission line is not good, especially the shielding performance is poor, or the power supply system has clutter, or there may be a strong interference source near the system.
Large area moire interference, also known as single-frequency interference. This phenomenon is mainly caused by the short circuit caused by the short-circuit of the video cable's core wire and the shield, or the failure caused by the open circuit, or due to the bad contact of the BNC connector.
5, equipment failure caused by power problems, there are the following possibilities:
· Incorrect supply line or supply voltage;
• The power is not enough (or the line of a certain power supply line is enough, the voltage is too big, etc.) The transmission line of the power supply system has a short circuit, open circuit, and instantaneous overvoltage.
Power supply interference and transmission stability It should be noted that due to power supply errors or instantaneous overvoltages, equipment damage may occur. Therefore, before the supply of electricity, it must be carefully and strictly checked and checked. It must not be taken lightly.
6, due to the video cable's core and shielding network short circuit, open circuit caused by the failure. This kind of failure manifests itself in a deep and chaotic large-area moire on the monitor, so that the image is completely destroyed and images and synchronization signals cannot be formed. This happens mostly on BNC connectors or other types of video connectors. That is, when such a fault occurs, it is not always a problem in the entire signal line, but merely in the number of unfavorable connections. As long as these joints are carefully checked one by one, it can be solved.
7. Space radiation interference introduced by the transmission line. The reason for this interference phenomenon is that there are strong and high-frequency space radiation sources near the transmission system, the system front-end, or the central control room. The first solution to this situation is to build a system, to achieve a comprehensive understanding of the surrounding environment, and then try to avoid or stay away from radiation sources; Second, when the radiation source can not be avoided, the front-end and center equipment to strengthen the shielding, The pipeline of the transmission line adopts steel pipe and is well grounded.
8. The pan/tilt's faulty pan/tilt common faults often do not work well in use or cannot be turned at all. In addition to product quality reasons, this situation is generally caused by the following reasons: • The pan/tilt head that only allows the camera to be mounted is lifted during use. The hoisting method leads to an increase in the operational load of the pan/tilt. Therefore, the use of the hoisting system will soon lead to damage to the drive mechanism of the pan/tilt, or even the total weight of the motor/camera and its protective cover will exceed the weight of the pan/tilt. Especially for PTZs that are used outdoors, the weight of the protective cover is often too large, and the problem of the pan/tilt moving (especially the vertical direction) often occurs. The outdoor pan/tilt is exposed to high ambient temperature, low or waterproof, and frost-proof. Such as poor performance and failure or even damage;
• When the distance is too far, the camera (including the lens) and the pan/tilt cannot be controlled by the decoder through the operation keyboard. This is mainly because when the distance is too far, the attenuation of the control signal is too great and the control signal received by the decoder is too weak. At this time, a relay box should be installed at a certain distance to amplify the control signal.
2. The mismatch of the characteristic impedance of the transmission cable may cause some vertical bars with equal spacing on the monitor screen, and the frequency of the interference signal is basically an integral multiple of the line frequency. This interference phenomenon is caused by the fact that the characteristic impedance and distribution parameters of the video cable do not meet the requirements. For such interference, the impedance of each device in the system should be matched as much as possible. Especially when the video cable is purchased, the cable quality must be ensured. If necessary, the cable should be sampled and tested.
3, the communication interface or communication protocol and other parameters are not set well, this situation often occurs between the control host and decoder or control keyboard and other devices with communication control relationship. In other words, the selected control host and decoder or control keyboard, etc., are not set during the installation of the communication protocol and other parameters, so the host, decoder, control keyboard, etc. should pay attention to the communication protocol and other parameters during installation Settings.
4. Common faults of video interference.
• A black bar or white bar appears on the monitor screen and scrolls up or down, which is the so-called 50 Hz power frequency interference. This kind of interference is caused by the potential difference loop caused by the improper grounding of the two devices at the front end and the control center. It may also be caused by the degradation of the power supply performance of the device itself.
Image has snowflake noise. This type of interference is mainly caused by signal attenuation on the transmission line and coupling of high-frequency interference. The video image has ghosting, or the image is whitish, the character is jittery, or there are several pitches on the monitor screen. Equal vertical bars interfere. This is because the characteristic impedance between the video transmission line or the equipment is not 75Ω, resulting in impedance mismatch;
Twill interference, jitter, power interference. When this interference is slight, it does not overwhelm the normal image, but when it is severe, the image is distorted and cannot be viewed. The reasons for this are more and more complicated. For example, the quality of the video transmission line is not good, especially the shielding performance is poor, or the power supply system has clutter, or there may be a strong interference source near the system.
Large area moire interference, also known as single-frequency interference. This phenomenon is mainly caused by the short circuit caused by the short-circuit of the video cable's core wire and the shield, or the failure caused by the open circuit, or due to the bad contact of the BNC connector.
5, equipment failure caused by power problems, there are the following possibilities:
· Incorrect supply line or supply voltage;
• The power is not enough (or the line of a certain power supply line is enough, the voltage is too big, etc.) The transmission line of the power supply system has a short circuit, open circuit, and instantaneous overvoltage.
Power supply interference and transmission stability It should be noted that due to power supply errors or instantaneous overvoltages, equipment damage may occur. Therefore, before the supply of electricity, it must be carefully and strictly checked and checked. It must not be taken lightly.
6, due to the video cable's core and shielding network short circuit, open circuit caused by the failure. This kind of failure manifests itself in a deep and chaotic large-area moire on the monitor, so that the image is completely destroyed and images and synchronization signals cannot be formed. This happens mostly on BNC connectors or other types of video connectors. That is, when such a fault occurs, it is not always a problem in the entire signal line, but merely in the number of unfavorable connections. As long as these joints are carefully checked one by one, it can be solved.
7. Space radiation interference introduced by the transmission line. The reason for this interference phenomenon is that there are strong and high-frequency space radiation sources near the transmission system, the system front-end, or the central control room. The first solution to this situation is to build a system, to achieve a comprehensive understanding of the surrounding environment, and then try to avoid or stay away from radiation sources; Second, when the radiation source can not be avoided, the front-end and center equipment to strengthen the shielding, The pipeline of the transmission line adopts steel pipe and is well grounded.
8. The pan/tilt's faulty pan/tilt common faults often do not work well in use or cannot be turned at all. In addition to product quality reasons, this situation is generally caused by the following reasons: • The pan/tilt head that only allows the camera to be mounted is lifted during use. The hoisting method leads to an increase in the operational load of the pan/tilt. Therefore, the use of the hoisting system will soon lead to damage to the drive mechanism of the pan/tilt, or even the total weight of the motor/camera and its protective cover will exceed the weight of the pan/tilt. Especially for PTZs that are used outdoors, the weight of the protective cover is often too large, and the problem of the pan/tilt moving (especially the vertical direction) often occurs. The outdoor pan/tilt is exposed to high ambient temperature, low or waterproof, and frost-proof. Such as poor performance and failure or even damage;
• When the distance is too far, the camera (including the lens) and the pan/tilt cannot be controlled by the decoder through the operation keyboard. This is mainly because when the distance is too far, the attenuation of the control signal is too great and the control signal received by the decoder is too weak. At this time, a relay box should be installed at a certain distance to amplify the control signal.
Gate valve is a gate opening and closing gate, the direction of movement of the gate and fluid perpendicular to the gate valve can only be fully open and fully closed, can not be adjusted and throttling. Valve through the valve seat and gate contact seal, usually sealing surface will be surfacing metal materials to increase the wear resistance, such as surfacing 1Cr13, STL6, stainless steel and so on. Gate valve is divided into rigid gate valve and flexible gate valve.
Material: Cast Iron, Ductile Iron,Carbon steel,Stainless steel
Type: Flanged, Screwed, Grooved
Standard: Class 125 to Class 250, or PN16 to PN25.
Size: 2" to 14"
Application: Pipelines with Water, Oil, Gas.
All other details or types, please send free requirments.
1.BS5150
2. DIN3352
Gate Valves,Flange Gate Valve,Resilent Seated Gate Valve,Grooved Gate Valve
HEBEI ZIFENG NEW ENERGY TECHNOLOGY CO.,LTD. , https://www.zifengpipeline.com