| 摘要 |
<p>When an underground pipe carrying a fluid, such as a buried water-pipe, develops a leak the leak must first be located before it can be repaired. One common location method makes use of the fact that the leaking fluid often creates a noise, typically a hissing sound, which is transmitted through the ground, and although rapidly attenuated can be heard with suitable highly sensitive ground microphones and is therefore useful to field crews as a means of locating leaks. Unfortunately, the sound levels can be grossly distorted by underground heterogenities, and can easily be confused or even swamped by other sound sources above ground, and in general ground microphones used like this do not seem to be effective. The invention deals with the problems entailed in this technique by a method - and apparatus - which involves using semi-automated equipment to listen (either simultaneously or sequentially) to the leak sound source (1) from a multiplicity of different positions (as 3) spaced all around the sound source, and by then suitably combining and processing the received signals to provide the desired indication of the source's location.</p> |
