There are a number of techniques available for locating unknown lines in an area. Using these techniques is particularly important before conducting any excavation work to help ensure that buried lines are not damaged.
Passive sweep
A passive sweep is used to locate Power, Radio, CATV or CPS signals that may radiate from buried conductors.
To perform a passive sweep:
- Press the
key to select the passive frequency you wish to locate. You can select from the following passive frequencies:
- Power
- Radio
- CATV (Cable TV)
- CPS (Cathodic Protection System)
- PASSIV (simultaneously detects Power and Radio signals where present)
- Adjust the sensitivity to maximum; reduce the sensitivity to keep the bar graph on scale when there is a response.
- Traverse the area in a grid search, at a steady walk, and hold the locator comfortably with the antenna in line with the direction of movement and at right angles to any lines that may be crossed.
Passive sweep
Stop when the locator response rises to indicate the presence of a line. Pinpoint the line and mark its position. Trace the line out of the area being searched. Resume grid search in the area.
In some areas there may be a confusing amount of 50 / 60Hz power signals. Lift the locator 50mm / 2” from the ground and continue the sweep, or use the 
key to switch from Power mode and use Power Filters to discriminate individual lines.
Switch the locator to Radio Mode. Increase sensitivity to maximum and repeat the above grid search procedure over the area. Pinpoint, mark, and trace out any lines that are located.
In most, but not all areas, radio mode will locate lines that do not radiate power signals and a grid search should be made in both power and radio modes or in Passive Avoidance mode.