How to solve the signal interference when borehole inspection camera work in deep well?
If there are strong sources of interference near the deep borehole inspection system, it can be judged by investigation and understanding. If this is the reason, the solution is to strengthen the shielding of the camera and ground the video cable.
Caused by the power supply system;power is not "clean". The power supply here is not "clean", which means that the interference signal is superimposed on the normal power supply (50-week sine wave). The interference signals on this kind of power supply mostly come from the equipment that uses SCR in this power grid. In particular, high-current, high-voltage thyristor equipment has a serious pollution on the power grid, which results in the power supply in the same power grid not being "clean". For example, there are high-power thyristor frequency and speed regulation devices, thyristor rectifiers, thyristor AC-DC converters in the power grid, which will pollute the power supply. The solution to this situation is relatively simple, as long as the entire system uses purified power or online UPS power supply can basically be solved.
The quality of the video transmission line is not good, especially the shielding performance is poor (the shielding network is not a good quality copper wire network, or the shielding network is too thin to play a shielding role). At the same time, the line resistance of this type of video cable is too large, so that the signal is greatly attenuated is also the cause of the increased failure. In addition, the characteristic impedance of this type of video cable is not 75Ω and the parameters are beyond the specifications is also one of the reasons for the failure. Because the above-mentioned interference phenomenon is not necessarily a failure caused by a bad video line, the cause of this failure must be accurate and cautious in judgment. Only when other possibilities have been ruled out can we consider it from the perspective of poor video lines. If it is really a cable quality problem, the best way is of course to replace all such cables and replace them with cables that meet the requirements. This is the best way to completely solve the problem.