Nulling out a previously detected buried utility can be carried out by placing the Genny on its side directly over the previously detected utility.
Airborne signal from the Genny can lead to confusing results. To confirm whether the CAT is detecting airborne signal or signal from below, use the technique outlined here.
- With the Genny switched on and inducing a signal into the ground, adjust the CAT sensitivity so that a low but clearly audible signal is received. Move the CAT through the signal and ensure that the signal increases and decreases.
- Keeping the CAT across the assumed route of the buried utility, aim the CAT directly towards the Genny. If the signal stays the same or increases, the signal is airborne.
- If the signal decreases or disappears, the signal is coming from a buried utility.
The figures
3 from the printed chapter
