Bench Tests - Garrett AT Pro Owner's Manual

BENCH TESTS

you should conduct bench tests to become more familiar
with the AT Pro's operation in both Standard and PRO modes.
In addition, the use of the Iron Audio feature should be tested
in both Standard and PRO modes. Suggested test items
should include:
• Coins
• Iron nail
• Bottle cap or steel washer
To conduct a bench test, place the searchcoil on a flat,
non-metallic surface that is several feet from other metallic
objects. Begin by testing in the STD Mode with the ZERO
discrimination pattern. Pass the coins individually across the
searchcoil at a distance of 3 to 4 inches. Listen to the audio
tone that the detector produces for each coin while also
observing the Target ID for each. Next, select the PRO Mode
For bench testing, place the searchcoil on a flat, stable, non-metallic
surface that is several feet from other metallic objects.
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with ZERO discrimination and pass the same coins across the
searchcoil. Observe the sounds as well as the Target ID as
each target is tested.
The proportional audio characteristics of the PRO Mode
can be easily understood using such bench testing. Pass
the coins across the searchcoil at distances that vary from 2
inches to 4 inches to 6 inches. In STD Modes, the test targets
will produce a consistent, full-strength tone regardless of their
distance from the coil.
Discrimination bench test: A similar test procedure can
be used to better understand how to set discrimination levels
and the AT Pro's advanced audio characteristics. Begin by
testing the iron nail in the STD and PRO Modes with the
ZERO discrimination pattern. Listen to the Low-Tone sound an
iron object creates and note the Digital Target ID number it
produces.
If the iron nail registers up to a 26 on the Digital
Target ID, use the IRON DISC pushbuttons to move the Iron
Discrimination setting up to 26. Pass the iron nail across
the searchcoil again to verify that it has been eliminated. If
not, raise the Iron Discrimination setting a little higher using
the (+) IRON DISC touchpad until the iron target no longer
produces an audible response.
Next, press the IRON AUDIO pushbutton and pass the iron
nail across the searchcoil again. Test this target both in STD
and PRO Modes with the Iron Audio feature switched on.
Iron Audio bench test: Flat iron objects like bottle caps
or steel washers can appear to be good conductive targets
to detectors operating in the standard mode. To better
understand the benefits of Iron Audio, use a bottle cap to test
the AT Pro's advanced audio features.
First, set the detector to Standard Mode with Zero
discrimination and pass the bottle cap across the searchcoil
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AT Pro™