FIELD: physics.
SUBSTANCE: method includes using a generator in an unfilled pipeline, which is a waveguide, to transmit a signal at a certain frequency, receiving the signal with an acoustic signal emitter, converting to an acoustic signal which is further transmitted through the waveguide, reaches the closed volume of the manhole and propagates through the ground. Presence of a rapture in the pipeline at the point of linking with the manhole and the smaller thickness of the ground over the manhole than over the pipeline enables strength of the acoustic signal over the manhole to be greater than over the pipeline. The location of the manhole is determined from the high strength of the acoustic signal received by an acoustic sensor connected to a receiver tuned to the frequency of the generator. Said method and apparatus can be used in public utilities when searching for manholes hidden under a layer of soil, asphalt, snow etc.
EFFECT: detecting manholes hidden under a layer of soil, asphalt or snow, regardless of the material of the manhole covers or communications themselves, longer range of detecting manholes from a signal source, low cost of equipment needed to detect manholes, low cost of training personnel owing to a simple search method, safer operation for personnel.
2 cl, 2 dwg
