Ground Balancing - Omega 8500 Owner's Manual

GROUND BALANCING

WH T IS GROUND B L NCING?
Why do I need to Ground Balance?
All soils contain minerals. Signals from ground minerals are often tens
or hundreds of times as strong as the signal from a buried metal
object. The magnetism of iron minerals, found in nearly all soils,
causes one type of interfering signal. Dissolved mineral salts, found
in some soils, are electrically conductive, causing another
type of interfering signal.
Ground Balancing is the process by which the metal detector
cancels the unwanted signals coming from the ground
minerals while still detecting the signals from buried metal
objects. This is accomplished by matching the detector's
ground balance setting to the phase of the ground signal.
When the detector is calibrated to the soil, the result will be deeper target
detection, quieter operation, and more accurate target identification.
1. Turn the detector on and set GAIN at the 12 o-clock position.
How to Ground Balance your Detector:
2. Click the right knob to All Metal Mode.
3. Adjust the THRESHOLD control knob to the point where you can hear
a slight background hum.
4. Sweep searchcoil across the ground to find a clear patch of ground
with no metal present.
5. Press and hold
the clean ground, keeping it level with the ground. Start about 6"
above the ground and lower to within 1" of the ground. See illustration
above.
6. When the ground phase value number displayed in the screen center
settles down to an unchanging number, the detector has been ground
balance. Release
If during this process you see a blinking arrow in the Ground Error window that
indicates an automatic GROUND GRAB OFFSET has been programmed.
Understanding ground conditions assists the user in setting up the detector,
knowing when to readjust ground balance, and in understanding the
responses of the detector while searching.
This detector provides two kinds of ground data:
1. The type of mineralization (which affects where the ground phase should
be set.) This is GND PHASE.
2. The amount of mineralization (the greater the amount of mineralization,
the greater the loss of detection depth & ID accuracy; the loss is more
pronounced in Discrimination Mode. This is the Fe
touch pad, and pump searchcoil repeatedly over
touch pad.
O
3 4
Ground Balancing continued on next page
Pumping coil
to ground
balance with
Ground Grab
button.
.
19