38 Garrett Metal Detectors
AT Gold
™
39
you should conduct bench tests to become more familiar
with the
AT Gold
’s operation in both All MeTAl and
Discrimination Modes. In addition, the use of the Iron Audio
feature should be tested in each mode. Suggested test items
should include:
• Various size gold nuggets or small gold ring
(In the absence of gold nuggets, a u.S. nickel or small
bronze coin are good imitators of the response
characteristics of a similar size nugget.)
• 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 All MeTAl Mode. Pass the
test items individually across the searchcoil at a distance of
For bench testing, place the searchcoil on a flat, stable, non-metallic
surface that is several feet from other metallic objects.
BeNCH TeSTS
3 to 4 inches (8–10cm). Observe the Target ID for each. Next,
select the DISC 1 Mode and pass the same targets across the
searchcoil. Notice that the proportional audio characteristics
and Tone ID responses sound similar in either the All MeTAl
or Discrimination Modes. use both large and small test pieces
at varying distances from the searchcoil to observe the levels
of their responses.
Discrimination bench test:
A similar test procedure can
be used to better understand how to set iron discrimination
levels. Pass the iron nail across the searchcoil while in either
DISC 1 or DISC 2 Mode. Note that in DISC 1 Mode, with the
factory preset level of zero (0) Iron Discrimination, the nail
produces a Medium Tone. 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. The factory preset
Iron Discrimination level of 35 in DISC 2 will eliminate most
iron nails from detection without adjustment.
Iron Audio bench test:
Next, remain in DISC 1 or DISC
2 with your Iron Discrimination level set to remove the iron
nail tested in the example above. Press the IrON AuDIO
pushbutton and pass the nail across the searchcoil again to
hear the distinctive iron sounds. Then, test this nail in the All
MeTAl Mode. Switch on the Iron Audio feature, set IrON DISC
to 26, and pass the nail completely across the searchcoil
again. The distinctive low-Medium-low response indicates
that the target is unmistakably iron.
Flat iron objects like bottle caps or steel washers can
appear to be good conductive targets to detectors. To test the
AT Gold
's advanced iron recognition abilities, conduct another
