Locating a Blockage in a Non-metallic Pipe
The basic procedure used in all of the previous
applications also can be used to locate a blockage
in a non-conductive (plastic, for example) pipe. In this
case, the + terminal of transmitter is connected to a
metal tube or piece of flexible conduit thin enough to
be fed into the pipe, as shown in Fig. 9.
When the signal induced in the receiver drops off
sharply, the receiver is directly above the blockage.
Locating a Metal Water Pipe
The basic procedure used in all of the previous
applications can even be used to detect the presence
of a hot or cold water pipe made of metal (such as galvanized steel).
Before proceeding:
• Make sure that all electrical equipment connected to the water distribution system is
powered off.
• Make sure that the pipe to be located is not grounded. If the impedance between the pipe
and ground is not large enough, the location distance will be very short.
•Use a wire to connect the transmitter’s
jack to ground.
11
Fig. 9. Locating a
blockage in a
non-metallic pipe
Fig 10. Locating a cold (left) or hot (right) metal water pipe