Garrett AT Max Manual page 16

Tip for using Iron Audio: In areas with high concentrations of
iron, it is recommended to switch off Iron Audio. Otherwise, it may
produce far too many signals. Then, if a target is detected that has
a questionable or inconsistent response, switch on Iron Audio to
check if it is iron.
To fully appreciate the additional information offered by the
Iron Audio feature, conduct the following experiment using a
bottle cap and a coin. Start with the AT Max in Zero Mode, with
Iron Disc set to 35 and Iron Audio off. Pass the bottle cap flat over
the searchcoil at approximately 4 inches (10cm). Note the subtle
breaks and inconsistencies of the target response, indicating it
might be a good target or it might be made of iron. Next, pass the
coin flat over the searchcoil and note the clean, High-Tone ID.
Now, switch on Iron Audio and pass the bottle cap flat over the
searchcoil again. The distinctive Low-High-Low response indicates
a target that is unmistakably iron. Note that the coin still produces
a clean, High-Tone ID. (See illustration below.)
Used in Disc Mode
Bottle
cap
Bottle caps, steel washers and other flat iron objects often sound like good
targets to standard detectors. This is because the bottle cap's shape and flat
surface resembles a coin which can trick the detector. With the AT Max's Iron
Audio, however, the ferrous bottle cap will produce a very distinctive response
with multiple tones, including Low-Tone flanking audio. As shown, the bottle cap
will produce a distinctive response of Low-High-Low as compared to the coin's
response of only High tone.
30 Garrett Metal Detectors
Iron Audio
Coin
Iron Audio Use in ALL METAL Mode:
In the ALL METAL Mode, all metallic targets encountered by
the AT Max are normally identified by a medium tone. The use of
the Iron Audio feature, however, allows the introduction of a low-
tone response to audibly indicate the ferrous content of targets.
This Iron Audio feature in a True All Metal Mode metal detector is
a Garrett exclusive.
The Iron Audio feature should be used in the All Metal Mode
as a means to check targets for iron content. Therefore, it is not
recommended to hunt with the Iron Audio feature continually
switched on.
To fully appreciate All Metal Iron Audio, use an iron nail and
a coin to experiment. Select the ALL METAL Mode, temporarily
switch on Iron Audio, and set the IRON DISC to 35. (Note: Iron
Audio must be switched on in order to set Iron Discrimination in the
ALL METAL Mode.) Switch Iron Audio back off and pass the nail
over the searchcoil. The nail will respond with a clean medium
tone, similar to that of a good target, such as the coin. Now, switch
on Iron Audio and separately pass the two targets completely
over the coil again. The distinctive Low-Medium-Low response of
the nail now indicates a target that is unmistakably iron. Note that
the coin, however, continues to respond with a clean medium
tone.
Refer to the illustration below regarding the use of the Iron
Audio feature in the All Metal Mode:
Low-Tone
IRON AUDIO ON: In All Metal Mode with this example, iron targets below 35 are
now heard with flanking low tones and targets above 35 produce a clean medium
tone.
Mid-Tone
31
AT Max
™