Page of 62
3 vLocPro Receiver
3.3.3 Null Mode
3.3.4 Sonde Mode
This uses vertical antennas and provides a minimum or “Null”
response over the center of the radiated signal from the
buried line. The compass line direction indicator shows the
direction of the cable (available in Active modes). The color of
the compass changed from clear to blue when the receiver is
in line with the buried line.
Pushbutton Icon
Sonde mode uses the antennas in a “Peak” configuration. An ICON on the display indicates if the
receiver is in Sonde mode.
A Sonde is a small transmitting coil that is powered by its own internal battery, or by an external
transmitter.
Due to its construction, a Sonde gives a different “Peak” pattern – when locating along the
direction of the Sonde – instead of the usual single “Peak”, the Sonde provides three distinct
peaks – a small “Peak” – a large “Peak” – a small “Peak”. The Sonde is located under the center
of the large “Peak” when located across the direction of the Sonde and it gives the conventional
peak response. Note that the Compass Line Indicator points across the line of the Sonde when
directly over it and the color of the compass change from clear to blue.
Pushbutton
Compass Line
Direction Indicator
Some users prefer the null response; it works well in uncongested areas, but is more prone to
inaccuracies due to distortion of the radiated signal in congested areas.
Left/right indication arrows are also displayed when in “Null” mode. The arrows indicate the
direction to move the receiver to locate the position of the buried line.
Icon
Compass
Line
Direction
Indicator
