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3 vLoc3-DM Receiver Functions and Operations
3.9 Classic Locating Modes (Response)
The vLoc3-DM receiver has an array of six antennas and these can be toggled through different configurations (modes) to
provide different responses to the signals radiating from buried utilities. The modes are:
Peak Mode
Two horizontal antennas provide a “Peak” or maximum signal response over the buried line.
This is an accurate locating method as both horizontal antennas are used to provide a clearly
identifiable peak. It is also less prone to the effects of signal distortion.
The Peak Level Indicator on the bar graph indicates the point of the largest signal detected allowing
the user to return to this point quickly.
The compass (line direction indicator) aligns itself parallel to the cable (available in Active modes).
Broad Peak Mode
A single horizontal antenna provides a “Peak” or maximum signal response over the buried line.
The result is a less defined peak than the twin horizontal antenna peak mode. This mode is useful
in deep lines because using a single antenna can boost the received signal.
The compass (line direction indicator) aligns itself parallel to the cable (available in active modes).
Null Mode
The vertical Null antennas receive a minimum or “Null” response over the buried line.
The null mode works well in uncongested areas but is more prone to inaccuracies due to the effects
of field distortion. This effect can be used to detect distorted fields by comparing the null mode
position with the peak mode position. If the two positions do not coincide, this indicates possible
distortion. The greater the difference, the greater the distortion.
Left/right arrows indicate the direction to move the receiver to locate the buried line's position while
in the null mode.
The compass (line direction indicator) aligns itself parallel to the direction of the cable (available in
active modes).
Delta Null
The Delta mode uses dual vertical antennas. The “Delta Null” has the advantage that it provides a
sharper response than the null mode and is less affected by distorted fields. All other functions are
the same as the null mode.
Delta mode uses dual null antennas to minimize the offset effects of field distortion. This mode
tends to be more precise than the Null mode.
