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7 Tracing Techniques and Helpful Information
Position of Transmitter for minimum interference
7.12 Locating a Service Lateral
After you have traced the main, you may want to go back and locate the service
laterals off the main. Service lateral traces are easiest to conduct in the Inductive
Mode. Two operators are required for this procedure – Operator 1 remains stationary
holding the Receiver as if to trace over and parallel to the main. Operator 2, carrying
the Transmitter (with the power on) and maintaining a minimum of 100 ft. between
himself and the Receiver, walks parallel, but 5 feet from the main on the side, he
expects to find the service laterals as shown in below. The field strength reading
on the Receiver will increase as Operator 2 crosses over the service lateral with
the Transmitter. Each time the field strength reading increases, Operator 1 signals
Operator 2 and he/she marks the lateral location on the ground.
Locating Service Laterals
7.13 Valves, Manhole Covers, Tees and Risers
If the meter reading suddenly increases and then falls back while tracing a pipe, you
have probably passed over a buried valve, manhole cover, tee, or riser.
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