The safety of explosion-proof cameras is of great importance. If they cannot be effectively monitored, there will be great danger in industrial production.  People who are engaged in the construction and installation of security monitoring will encounter the phenomenon that explosion-proof monitoring cameras do not display pictures during use.  When there is no image in the explosion-proof camera, don't worry, first check whether there is a problem with the circuit and wiring. If it is an explosion-proof infrared camera, you can check whether the infrared lamp is still on. If it is an explosion-proof camera without infrared, you can use a multimeter to check whether there is any electricity delivery. It is also possible that there is a problem with the hard disk video recorder in the storage part.  Faced with these many problems, where should we start?  The following analysis and solutions to common failures of these explosion-proof cameras are for your reference.  The explosion-proof camera has its own fault. If the camera is electrified normally, but the camera has no image, it can be preliminarily judged to be the explosion-proof camera's own fault.  Assuming that only the camera of this analog explosion-proof monitoring camera manufacturer has this fault, then the problem may occur when the internal program of the monitoring camera of the analog camera manufacturer crashes.  Solution: It can be recovered after power failure and restart, mainly caused by bad reset circuit.  The power supply of explosion-proof cameras is insufficient. Currently, the power supply quality of explosion-proof cameras is generally good, but it does not rule out the reason of instability or failure over time.  The power of the switching power supply itself is not enough, which causes the switching power supply to overheat, thus causing thermal protection. The inspection method is to check whether the power supply has temperature on site. If it is cold, the power supply will crash.  Solution: Replace the power supply.  In general, the video line and the power line touch line have the protection function on the camera chip. A short-term touch line will not cause fatal damage to the camera product. If the voltage is 22v, it is hard to say.  The line has power supply: if it is overlapped with AC power on the video transmission line, it will cause the electrolytic capacitor inside the monitor camera head and distributor to charge, thus blocking the video signal output.  Test method: Use multimeter to measure the voltage of video cable.  Solution: Find the place where the power supply is overlapped or add an anti-interference device. The anti-interference device has a full isolation function in order to prevent the occurrence of similar phenomena. In addition, the maximum voltage can be 220V on the video circuit while the equipment can still work normally and will not be transmitted to the explosion-proof monitoring camera or the main control room.  During the construction of the project, the lines are connected reversely. Sometimes we will connect the positive and negative poles of the explosion-proof camera lines reversely. Generally, it is ok to switch them over.  Too fine leads to large pressure drop, and the analog camera manufacturer's camera cannot be started.  Solution: During normal construction, the analog camera manufacturer prompts the multimeter to measure the input voltage and current of the camera.  Other precautions explosion-proof cameras should be installed and used with the same caution.  The inlet of explosion-proof camera must be sealed with rubber sealing ring. It is strictly prohibited to arbitrarily change the structure, components and internal lines of equipment of explosion-proof camera.  Fastening bolts shall not be replaced or missing at will. The redundant elastic gasket and metal gasket at the wire inlet and outlet must be kept in the factory sealed state, and the compression nut shall be tightened to seal the wire inlet.  It is better to use dark lines for wiring. If there is really no way to use open lines, it is necessary to ensure that the physical protection of the line part is the best.  Attention should be paid to avoid strong impact on the explosion-proof infrared camera during installation. During routine operation and maintenance inspection, the explosion-proof camera housing should be avoided as much as possible. When it must be opened, the power supply should be cut off first.  The explosion-proof infrared camera uses infrared light emitted by an infrared lamp matched with a ccd to reflect the infrared light on an object to the lens of the ccd camera for imaging.  Therefore, when installing the explosion-proof infrared camera, all black objects, empty places, water and other objects that absorb infrared rays should be avoided. If infrared rays are absorbed or weakened, the effective irradiation effect of infrared lamps will be greatly reduced, thus affecting the monitoring picture effect of the explosion-proof infrared camera.  In short, the installation and construction wiring of explosion-proof cameras should be very careful. In case of any problem, the troubleshooting method should be adopted to find out the cause of the problem and solve it.  Generally speaking, the explosion-proof monitoring equipment of brand manufacturers has been debugged before leaving the factory, and the probability of problems is relatively low.  However, some new project customers are prone to problems when they are not very clear about it, such as the first installation. Therefore, the main problem is experience. If they do more, they will know roughly how to eliminate these problems.  Another thing to remind is that in chemical plants, there are explosive gases and dust in some environments, so don't repair them directly. It is easy to cause accidents. The correct way is to take out the explosion-proof camera after power failure and take it to a safe environment for testing and maintenance.