In modern communications, energy, transportation and other fields, optical cables are used as infrastructure for information and power transmission, and their buried density and complexity are increasing day by day. In order to more efficiently and accurately grasp the direction, location and fault points of underground optical cables, optical cable routing detectors have become an indispensable technical tool.
The optical cable routing detector is a high-tech product designed based on the principle of electromagnetic induction, based on the step voltage theory, combined with digital filtering, wireless reception and software control.
The basic working principle of electromagnetic induction is: the transmitter generates electric and magnetic waves and transmits the transmission signal to the underground metal pipeline to be detected through different transmission connection methods. After the underground metal pipeline senses the electromagnetic wave, an induced current is generated on the surface of the underground metal pipeline. The induced current will propagate along the metal pipeline to a distance. During the propagation of the current, the electromagnetic wave will be radiated to the ground through the underground metal pipeline. In this way, when the optical cable routing detector receiver detects on the ground, it will receive the electromagnetic wave signal on the ground directly above the underground metal pipeline. The position and direction of the underground metal pipeline can be determined by the change in the strength of the received signal.
Conditions for the realization of this principle:
First, there must be a signal source that can generate enough electric energy to form a current in the line that can transmit electric energy. The current will generate a magnetic field around the line during the flow process; secondly, there must be a circuit that can receive this specific magnetic field and display the change process of the magnetic field in the form of an electrical signal. This process of changing from electricity to magnetism and then from magnetism to electricity is the basic principle of the optical cable routing detector.
Step voltage:
Secondly, it is necessary to ensure that the electric energy in the line flows to the point of the earth (leakage point), around which an electric field will be formed. It is centered on the leakage point and diffuses outward in the form of electric potential in a uniform decreasing manner. The electric potential of the same circle is equal. Secondly, there must be a circuit that can detect the potential difference and measure the equipotential circle. The center of the circle is the leakage point (cable fault point). This is the theoretical basis for the step voltage fixed point of the optical cable routing detector.