4. Locating Hidden Valve Caps and Manholes.
The 902 receiver incorporates a feature that makes locating
masses of metal buried below the surface simple and con-
venient. Activating the LOCATE MASS button reconfigures
the receiver antenna, making it sensitive to nearby metallic
masses, such as manholes and valve caps. A continuous
tone emerges from the receiver which changes frequency
when brought near a metallic mass. Details on using this
feature follow here
(see Figure 15)
.
a) At any time while you are tracing a line, you may press the
LOCATE MASS button. Once set to locate masses, the
receiver outputs a continuous tone.
b) Move with the receiver held flat to the surface beneath
which you a searching for a mass. In this mode, the
receiver is only sensitive to about 18 to 24 inches, so you
must search with the receiver held close to the surface.
Model 902 Pipe & Cable Locator
25