| 摘要 |
Sounds are generated in a pipe (20) using an audio speaker (3) connected to a standpipe (7) connected to the underground pipe (20) or in some other way. Those sounds propagate down the pipe and are detected remotely from the audio speaker (3) by a detector (21) having a doppler radar (22). This enables location of the pipe (20) at the site of the radar (22). This is applicable to other concealed pipes or cables and, for example, may be used to detect the mains hum of a cable to which the mains voltage is applied. |
