| 摘要 |
A buried pipe detection device based upon the principle of sensing of differences in the dielectric/conductive properties of the ground in the vicinity of the pipe is disclosed. Because the electrical properties of the ground directly over the buried pipe will differ from those of an area immediately adjacent to the pipe, the detection principle is embodied in a capacitor plate array that injects a low frequency sinusoidal signal into the ground and samples the injected signal from two spatially separated locations on the array. The capacitor plate array has two injector/sensor plates that form a capacitively coupled impedance bridge with the ground and a third plate to establish circuit ground. The injector/sensor plates sense changes in the ground path impedance directly beneath the plates as the array is moved along the ground. The outputs of the two sensor/injector plates are then combined differentially and are processed to provide a continuous analog or digital readout. As the capacitor plate array is moved along the ground, an operator observes the readout to detect and mark the location of the buried pipe. The operator, by pushing the instrumented capacitor plate array along the ground and observing the readout, may obtain a two dimensional map of the buried pipe.
|
