Device for searching fault points of cable or pipeline

Abstract

The invention relates to a device for searching fault points of a cable or a pipeline. The device for searching fault points of the cable or the pipeline comprises a transmitter and a receiver, wherein the transmitter is composed of a control system, a signal producing circuit, a signal amplification circuit, a gear shifting circuit or a voltage limiting circuit for alternating current or direct current output, a power detection circuit, a power regulating circuit, a impedance measurement circuit, an analogue/ digital (A/D) sampling circuit, a keyboard and a display device. The device for searching fault points of the cable or the pipeline comprises four detection circuiting methods: low-frequency alternating current detection method, high-frequency alternating current detection method, pulse detection method and impedance detection method. The four detection methods are used and provide evidence for each other, and thus fault points are determined reliably. When the cable or the pipeline is detected, cable or pipeline condition changes, cable line-breaking fault condition, cable insulation condition relative to the ground and the like are considered, and then fault points are found out.

Description

technical field [0001] The invention relates to a device for finding fault points of cables or pipelines. Background technique [0002] The traditional methods and devices for finding cable faults are as follows: [0003] The first one - pulse reflection echo method, this method is only suitable for finding cable faults. The finder sends a pulse signal to the checked core wire, and the signal wave is transmitted along the core wire to the terminal. If there is a sudden change in impedance (such as disconnection, short circuit, mixed wire, grounding, etc.), a transmission echo will be generated. Signal, according to the return time of this reflected signal, combined with the propagation speed of the signal wave in the core wire (ie wave speed), the distance to the fault can be calculated. The calculation method is: the distance to the fault point is equal to the echo reflection time multiplied by the wave speed Then divide by two. However, this method is only applicable to...

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Problems solved by technology

[0004] The second method - bridge method or parameter value method, this method is only suitable for finding cable faults

[0005] The third method - high-voltage discharge listening method, this method is only suitable for finding cable faults

[0008] The above-mentioned methods for finding fault points of wires, cables, and pipes are relatively simple, especially when the fault point is a high-impedance ground, or a fault with mixed wires and unstable ground resistance, or a fault point with large external interference. Under certain circumstances, it is difficult to effectively locate the fault point by only one method

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