Q: How does the interference occur during the detection process?
Answer: The pipeline locator detects the electromagnetic field generated by the applied signal current on the target metal pipeline. Ideally, the shape of the electromagnetic field should be a standard concentric circle. The most common cause of interference is that the signal on the target pipeline is coupled to the adjacent pipeline. The interfered electromagnetic field is a deformed electromagnetic field, which causes inaccurate readings. The higher the transmission frequency, the greater the interference of adjacent pipelines.
Q: Why do I detect interference signals on other pipelines?
Answer: In this case, the signal applied by the transmitter is shunted to other pipelines or coupled to other pipelines by mutual inductance through the common ground point. At this time, use the direct connection method to apply the signal, or change the signal application point, and use a lower frequency.
Question: How to verify the accuracy of peak positioning with the valley method?
Answer: For an ideal non-interference pipeline, the location of the wave crest/valley method is coincident. However, when there are parallel pipelines or other interferences, the positions of the peak/valley method positioning will not coincide. The true position of the pipeline at this time is on the side of the peak value. When the interference is severe, the zero point may not be found. At this time, the location of the pipeline can only be given based on the peak position. It is best to change the applied signal method and re-position the pipeline. When the positions measured by the wave crest/valley method do not coincide, the pipeline direct-reading bathymetry will have a large deviation, or even the depth cannot be read.
Question: Is there any way to reduce the deformation of the electromagnetic field shape of the pipeline?
Answer: First of all, you can try to reduce the output power of the transmitter. Sometimes the signal is too strong and the detection effect may not be the best, especially when multiple pipelines are parallel and very close. If you are using the induction method, you can switch to the direct connection method or the clamp method to apply the signal. This can reduce the signal coupled to other pipelines, thereby reducing the deformation of the electromagnetic field of the pipeline. If it is found that the valley method and the peak method positioning are inconsistent, change to a consistent place for positioning. If no consistent place is found, we usually use the peak position as the position of the pipeline. The depth measurement is also carried out in the peak mode, and of course there is also A certain error, but closer to the true value than the valley method.
Question: Can the device be used to detect copper cables and optical cables at the same time?
Answer: The current pipeline locator can only detect cables with metal sheaths or core wires. Only optical cables with a metal sheath or a central metal reinforcement core can be detected by underground pipelines. To detect the cable, a detectable signal (transmitter signal) must be applied to the conductor.
Q: Why is my receiver inaccurate?
Answer: 1. Check whether the correct working mode is selected, peak mode should be selected.
2. Check whether the positions of peak method and valley method are consistent. Although the method of direct reading sounding is simple, it requires certain conditions to read the correct results, otherwise the measurement accuracy will not be high, and even wrong results will be obtained. One of the conditions for applying direct reading sounding is that the peak and zero values at this time must basically coincide, otherwise the error will be large. The second is that the depth of direct reading must be corrected to achieve higher reliability. The correction factors include: the humidity of the pipeline buried soil and the frequency of the detection signal. Generally, the greater the soil humidity, the higher the detection frequency, and the correction coefficient is Should be smaller, generally between 0.8-0.95. The simple method is to find a pipe section with a known depth and no interference, measure the direct reading depth, and calculate the correction coefficient compared with the actual buried depth.
3. When measuring the buried depth, pay attention to the direction of the receiver, and try to make the receiver's coil and the pipeline perpendicular. This requirement can be achieved by turning the receiver slightly to make the display on the panel reach the maximum value. In addition, it should be noted that the direct reading buried depth value is the distance from the ground of the receiver body to the center of the pipeline.