14 Garrett Metal Detectors AT Max™ 15
All Metal Mode Audio Characteristics
While in the ALL METAL Mode, the AT Max will respond to the
entire range of conductive and magnetic properties encountered,
including ground responses.The user is continuously hearing what
the searchcoil is "seeing" in the ground. Therefore, it is essential to
be properly ground balanced while operating in the ALL METAL
Mode. Naturally occurring minerals in the soil must be canceled
out during the ground balance procedure in order to detect only
the signals from metal objects.
The ALL METAL Mode provides target information, including
a Target ID pixel on the upper scale, Digital Target ID, and depth
reading. The AT Max thus allows the operator to remain in the ALL
METAL Mode at all times, in contrast to some detectors which
require the operator to switch to a Discrimination mode to obtain
Target ID. Be aware that some deeper targets (faint audible signals)
may exceed the reach of Target ID.
Because the ALL METAL Mode permits no discrimination, the
detector will give an audible signal to indicate every piece of
metal it scans over. Target responses will normally be heard as a
proportional Medium Tone. However, the AT Max is a unique All
Metal detector in that its Iron Discrimination and Iron Audio™
features can be used to hear if detected targets are ferrous, as
indicated by a low tone. Iron Discrimination levels can only be
adjusted in the ALL METAL Mode if the Iron Audio feature is on;
note, these changes will not be retained when the detector is
switched off. (See Iron Audio section, pages 28–31.)
Gold prospectors and many relic hunters rely primarily on
their ears to discern good target signals. These desired signals
are presented as clean, repeatable responses that override the
background audio.
Discrimination Mode Audio Characteristics
The AT Max includes three Discrimination Modes: Custom, Coins,
and Zero. These modes are used to eliminate trash metal items
(e.g. foil, pull-tabs, nails) from detection and provide more Tone
ID information that the ALL METAL Mode. Discrimination filters
are introduced in these three modes, which can make them less
sensitive to small and deep targets than the ALL METAL MODE.
In its Discrimination Modes, the AT Max's Tone Roll Audio
provides the user with more target information to help identify
targets, particularly flat iron objects such as bottle caps and
washers, especially with Iron Audio switched on. Tone Roll Audio
provides a variance of target tones as the searchcoil approaches
and passes over the target. These varying tones of audio provide
better overall target information and identification.
