TIANJIN GREWIN TECHNOLOGY CO.,LTD.
Web:www.grewin-tech.com Wh86-13072088960
Email:[email protected]
TIANJIN GREWIN TECHNOLOGY CO.,LTD.
Address:
2# MeiNian Plaza No.16 DongTing Road,Hexi Distr,300222,Tianjin China
.
37
reliable or accurate, but they can also provide some information about the pipelines in the area to
be explored, and the sites: manhole covers, street lights, and signs indicating that there are buried
pipes and cables need to be considered.
2. Power Frequency Grid Scanning
The receiver is able to test the frequency of the power cable at 50Hz. This method can quickly
detect the position and orientation of underground power cables in the detected area and does
not require a transmitter.
Press the receiver frequency key and select 50Hz frequency and a working mode. Take the peak
mode as an example to illustrate the detection method: adjust the sensitivity so that the signal
strength is 60-80% of the full scale. Scan the area in the grid-like route. Make sure the direction of
the receiver is consistent with the direction of the pipeline and is at right angles to the measured
pipeline. When the receiver response increases, it means that there is a pipeline. Stop and position
the pipeline accurately. Mark the location of the pipeline and trace the pipeline until it leaves the
detected area. Then return to the area and continue network scanning.
Mark each pipeline location that has a signal response, then trace the portion of the pipeline
outside the area and mark it.
3. Inductive Search
Inductive search is the most reliable technique for detecting unknown pipelines. This method
requires a transmitter, a receiver, and two inspectors. This search method is called "two-person
search method." Before starting, determine the areas to search for and the possible directions
through which the pipeline passes. Turn on the transmitter, select the working mode as inductive
connection and the same frequency. One inspector operates the transmitter and the other
operates the receiver. Apply the signal to the pipeline when the transmitter passes through the
pipeline and the receiver can detect the signal 20 meters upstream or downstream of the
transmitter. The direction of the transmitter is consistent with the estimated direction of the
pipeline. One person holds the receiver at the beginning of the area to be searched and the
direction of the antenna of the receiver is kept perpendicular to the direction of the possible
underground pipeline. The receiver is adjusted to the highest sensitivity that will not receive the
transmitter signal directly from the air. When the direction of the transmitter and receiver is
correct, the two operators move forward in parallel. The operator carrying the receiver moves the
receiver back and forth while moving forward. The transmitter applies the signal to the pipeline
directly below and the receiver detects the signal.Mark the ground at the receiver's detected peak