The best use method and precautions of underground metal detectors; the underground pipeline detectors are divided into two categories according to the principle of detection, one is to use electromagnetic induction principle to detect metal pipelines, electric/optical cables, and some non-metallic pipelines with metal markers, which is referred to as pipeline detectors; the other is to use ultrasonic thickness detectors. Using electromagnetic wave to detect all underground pipelines can also be used to find buried objects, commonly known as radar, also known as pipeline radar.
Generally speaking, the underground pipeline detector is composed of two parts: transmitter and receiver. Transmitter: To apply a special frequency signal current to the pipeline under test, three excitation modes are generally adopted: direct connection method, induction method and clamp method. Receiver: The receiver has built-in induction coil, which receives the magnetic field signal of the pipeline. The coil generates the induction current, thus calculating the direction and path of the pipeline.
Generally speaking, the transmitter of underground pipeline detector has three receiving modes: peak mode (maximum), Valley mode (minimum) and wide peak mode; moreover, more advanced instruments now generally have peak arrow mode (combining the advantages of peak and valley value, making operation more intuitive) and compass guidance (used to indicate pipe). The direction of the line.
The underground pipeline detector uses the principle of electromagnetic induction to detect the precise direction and depth of underground metal pipelines and cables and the fault points on the outer surface of pipelines. The intellectualized full Chinese characters, graphic operation instructions and voice frequency modulation instructions of the underground pipeline detector make it the most easy-to-use underground pipeline detector nowadays. The transmitter built-in ohmmeter can automatically measure the loop resistance and the continuous automatic output impedance matching. The ultrasonic thickness gauge ensures the best matching signal output. According to the need of practical application, the coupling clamp can be selected to find the path of live cable without power failure. The 50Hz detection function of the receiver can also be used to track the 50Hz power frequency signals from the running cables, which truly achieves a multi-purpose machine and has the best performance-price ratio.
Its basic working principle is that the transmitter generates electromagnetic wave and transmits the transmitted signal to the underground metal pipeline detected by different transmission connection modes. After the underground metal pipeline senses the electromagnetic wave, it generates the induced current on the surface of the underground metal pipeline, and the induced current will propagate to a distance along the metal pipeline, and in electricity. In the process of flow propagation, electromagnetic wave will be radiated to the ground through the underground metal pipeline, so that when the receiver of underground pipeline detector detects on the ground, it will receive electromagnetic wave signal on the ground directly above the underground metal pipeline. Through the change of the received signal strength, it can distinguish the location of underground metal pipeline and the location of underground metal pipeline. Trend.