1. Compact size, lightweight, and easy to carry;
2. Simple detection method, easy maintenance, with automatic protection function;
3. Low power supply voltage, strong applicability;
4. High transmitter power and efficiency;
5. Small detection error, strong anti-interference capability;
6. Stable and reliable performance. It is a precise and reliable cable locating instrument used in departments such as communications, electric power, railways, factories and mines, and hydropower, to ensure quality inspection of underground cable construction and fault point maintenance inspection.
By sending a 1 kHz electromagnetic wave signal to the underground cable through the transmitter, the cable's direction and depth are determined using the principle that when the cable locator probe is perpendicular to the ground and tangent to the magnetic field lines, the received signal is minimal (almost zero). When the probe moves parallel to the ground and the signal sound suddenly becomes weaker, it indicates the open circuit point and short circuit point of the cable.
1. Zero method (minimum method): Place the probe perpendicular to the ground. When directly above the cable, the received signal is minimal (meter reading minimum). This detection method is called the zero method.
2. Peak method (maximum method): Place the probe parallel to the ground and perpendicular to the cable direction. When directly above the cable, the received signal is strongest (meter reading maximum). This detection method is called the peak method.
3. Depth detection: The principle for measuring burial depth is as follows: First, place the probe perpendicular to the ground to find point A directly above the cable (mark this point). Then tilt the probe at a 45-degree angle to the ground, keep it close to the ground, and move it sideways perpendicular to the cable direction to find the position B where the sound is minimal. As shown in the figure, the cable center is O, making triangle ABO an isosceles right triangle, so AB = AO, which represents the burial depth.
By sending a 1 kHz electromagnetic wave signal to the underground cable through the transmitter, when a fault occurs in the underground cable and breaks down, the core wire comes into contact with the lead sheath of the earth. If an AC signal is applied to the core wire or the lead sheath, a current loop forms at the fault point, generating a leakage signal that radiates to the ground, creating a leakage electric field in the earth. The radiation signal is strongest directly above the leak point. Using the two probes of the A-frame to pick up this gradient signal, by moving the A-frame, the strongest point of the leak signal can be found. Based on this principle, the fault point of the underground cable can be accurately located.
