Owner`s Manual - Garrett Metal Detectors

1881 W. State Street
Garland, Texas 75042
Owner’s Manual
The powerful, all-terrain solution for locating
deeply buried European coins and artefacts!
Tel: 1.972.494.6151
Email: sales@garrett.com
Fax: 1.972.494.1881
© 2012 Garrett Electronics, Inc. PN 1533300.C.1012
Owner’s Manual
Congratulations on the purchase of your new Garrett AT
Pro™ metal detector. This enhanced metal detector has
been specifically designed for use in Europe's challenging
The AT Pro includes Garrett's exclusive Target ID technology
and patented discrimination features. Two indicator scales
allow you to see the detector’s discrimination setting (Lower
Scale) as well as the analysis of each target (Upper Scale).
In addition, a Digital Target ID scale provides a more specific
target value. The AT Pro also features High Resolution
Iron Discrimination (40 points) for separating desirable
targets from iron junk in cluttered areas, several advanced
audio features and a standard 28x22cm elliptical Double-D
searchcoil engineered for optimum performance in Europe's
more challenging mineralised soils. In addition, the AT Pro
can be operated in a very user-friendly Standard (STD) Mode
or in a more advanced PRO Mode for experienced hunters.
Backed by more than 45 years of extensive research
and development, your Garrett AT Pro metal detector is
the most advanced of its kind in the industry. Whether you
are experienced or a beginner, this machine is well suited
for a wide variety of detecting environments. The AT Pro's
advanced features are designed for the expert treasure
hunter but its Standard Mode can be easily operated by the
In order to take full advantage of the special features and
functions of the AT Pro, you are urged to carefully read this
instruction manual in its entirety.
AT Pro International™
AT PRO CONTROL PANEL.................................................................... 4
QUICK START GUIDE............................................................................ 5
AT PRO COMPONENTS........................................................................ 6
LIST OF PARTS..................................................................................... 7
ASSEMBLY........................................................................................... 8
POWERING ON................................................................................... 11
SEARCH MODES................................................................................ 12
Overview of STD Mode vs PRO Mode���������������������������������������� 12
Standard (STD) Detection Modes���������������������������������������������� 13
PRO Detection Modes................................................................. 15
Proportional Audio (PRO Mode)������������������������������������������������� 15
Tone Roll Audio (PRO Mode)������������������������������������������������������ 18
TARGET ID INFORMATION................................................................. 19
DIGITAL TARGET ID............................................................................ 20
TONE ID.............................................................................................. 21
DISCRIMINATION............................................................................... 22
Notch Discrimination.................................................................. 22
Iron Discrimination...................................................................... 24
IRON AUDIO....................................................................................... 27
SENSITIVITY....................................................................................... 30
GROUND BALANCE............................................................................ 31
Automatic Ground Balance......................................................... 31
Manual Ground Balance............................................................. 32
FREQUENCY ADJUSTMENT............................................................... 33
PINPOINTING..................................................................................... 34
Narrowing the Detection Area��������������������������������������������������� 36
Coin Depth Indicator................................................................... 36
Alternative Pinpointing Methods����������������������������������������������� 37
HUNTING TIPS................................................................................... 39
BENCH TESTS.................................................................................... 44
UNDERWATER OPERATION............................................................... 47
CARE AND MAINTENANCE................................................................ 48
Battery Replacement.................................................................. 48
TROUBLESHOOTING GUIDE.............................................................. 50
METAL DETECTING CODE OF ETHICS��������������������������������������������� 51
CAUTIONS.......................................................................................... 52
WARRANTY / SERVICE...................................................................... 53
ACCESSORIES.................................................................................... 54
SUGGESTED READING...................................................................... 56
Garrett Metal Detectors
AT Pro International™
Target ID
metal types.
Target ID
Target ID
(also shows
ground balance
settings while in target identity.
GND-BAL mode.)
High Resolution
Iron Discrimination
indicates level of iron
discrimination selected.
Lower Scale
indicates notch
discrimination pattern.
Coin Depth
indicates depth of
coin-sized target.
1. Install batteries.
The AT Pro operates with four (4) AA batteries which are
already installed by Garrett.
2.Power ON.
Press and release the ON / OFF Power button. The AT Pro
powers on in the last mode used and is ready to search.
(Factory default mode is Coins.)
3.Select Mode.
Use the Mode Pushbutton to select a different detection
mode, when desired.
4.Adjust settings.
Adjust Sensitivity or Discrimination settings, if desired.
Iron Disc
Use (+) or (-) to change
iron discrimination
Iron Audio
Use to hear
ON / OFF Power: hold 1 second
to turn power on/off.
MODE: push quickly to toggle
between detection modes.
RESET: hold 5 seconds to restore
factory settings.
Press and hold to
pinpoint or use with
or (-) to change
increases or decreases sensitivity.
Garrett Metal Detectors
Battery Level
5.Begin scanning.
Lower the searchcoil to 2 to 3 cm above the ground and
scan the coil left and right at approximately 1m/second.
Press and hold for fast auto
ground balance or use with
NOTCH DISC (+) or (-) for
manual ground balance.
Use NOTCH DISC (+) or (-) to select
a cursor. Then use ELIM button to set
its discrimination on or off.
AT Pro International™
No tools are required to assemble the AT Pro. Four (4) AA
batteries are included with the detector. The box for your
detector contains the following parts:
Arm Cuff
 One (1) control housing with
S-shaped stem
 One (1) upper stem and one
(1) lower stem connected,
with camlock fasteners
 One (1) wing nut, two (2)
mounting washers and
one (1) threaded bolt
 One (1) 28x22 cm DD
 Owner's manual
 Warranty Card
If any part is missing, please contact your local dealer.
Garrett Metal Detectors
AT Pro International™
1. Holding the upper and lower stem assembly in front of you (as
shown below), twist camlock to the right (clockwise) to loosen.
2. Slide lower stem out to engage spring clips in upper stem holes.
3. Align the holes in the mounting washers with the small posts on
the lower stem and press firmly into place.
7. Depress the spring clip in the S-stem (containing control housing)
and insert S-stem through the upper camlock collar into the
upper stem.
8. The spring clip must be engaged in the FIRST stem opening in
order to maintain battery compartment access. Hand-tighten
the camlock collar. Do not overtighten!
1st pin position
9. Depress the spring clip in the lower stem and adjust to the most
comfortable operating length. Hand-tighten the lower stem
camlock collar. Do not overtighten!
10. Wrap the cable snugly about the stem with the first turn of the
cable over the stem.
4. Slide the searchcoil onto the stem.
5. Insert the threaded bolt through the holes of the lower stem and
searchcoil. Hand-tighten searchcoil assembly with the wing nut.
Holding assembly as shown, loosen camlock at the end of the
upper shaft by turning counter-clockwise.
Note: If the camlock collar slides off during loosening, simply
slide it back on and tighten slightly.
11.Insert the coil connector into the 4-pin connector of the control
housing and hand-tighten. After lining up the connector
pins, press the connector in firmly, yet carefully, until the O-ring
is felt to be fully inserted.
Note: If the O-ring is properly
seated, the connector's collar
can be easily tightened; if the
collar is difficult to turn, the
O-ring may not be seated
Garrett Metal Detectors
AT Pro International™
12.If needed, adjust the arm cuff by removing the screw on the
bottom. Move the two-piece cuff to the other hole, reinsert the
screw through the headphone cable clip, and tighten.
13.If desired, attach headphones to the 2-pin connector of the
Control Housing. After lining up the connector pins, press the
connector in firmly, yet carefully, until the O-ring is felt to be
fully inserted.
14.Secure the headphone cable under the detector's arm cuff by
pressing the cable into the headphone cable clip.
Note: Headphones are not required but are desired by many
hunters to hear faint targets. Connecting the headphones will
silence the detector's speaker.
Note: The provided headphones are for dry use only; see page
54 for optional waterproof headphones.
ON/OFF Power
and MODE
Switch the detector on with the power button.
Press and release to switch the unit ON and resume hunting
with the same settings used prior to switching the unit OFF.
To turn off the detector, press and hold this pushbutton for
one (1) second (until the detector produces a second beep).
To restore the factory settings, press and hold the power
button for 5 to 10 seconds (until the detector produces a fast
double beep).
10 Garrett Metal Detectors
AT Pro International™
The AT Pro includes six detection modes: three Standard
(STD) Modes and three Professional (PRO) Modes. It is
recommended to begin searching with one of the Standard
Modes to become familiar with the AT Pro before switching
to the more advanced audio features provided by the Pro
Tap the Mode button to scroll through the six modes:
the modes are Custom, Coins or Zero in the STD Mode and
Custom, Coins or Zero in the PRO Mode.
•Overview of STD Mode vs PRO Mode
In its Standard (STD) Mode, the AT Pro provides a fullstrength audio response regardless of a target’s amplitude.
Many detectorists prefer this consistent, unambiguous, binary
(either on or off) target response. The AT Pro's Standard Mode
operates in this clean, binary response format in which the
target's dominant conductivity is reported by a single tone.
This mode offers "quieter" or more stable operation and is
preferred by many beginners.
For those who want to hear more target information,
Garrett offers a Pro Mode. The benefits of operating in Pro
Mode include the ability to hear a target's size and depth via
the Proportional Audio and conductivity changes via Tone
Roll Audio. Pro Mode also offers faster recovery speed for
separating adjacent targets. The advanced audio features of
Pro Mode are intended for more skilled users who wish to
hear the true signature of targets versus the simpler target
response provided in STD Mode.
12 Garrett Metal Detectors
In the STD modes, the AT Pro produces a full-strength
binary audio beep to indicate a detected target. Standard
detection mode operation is ideal for learning the AT Pro
because of its consistent audio signals. Detected targets
are heard at the same full-strength beep regardless of their
size or depth.
Three discrimination patterns are available in the
Standard Mode: Zero, Coins or Custom.
Note: These three discrimination patterns are the same
in either Standard or Pro modes.
• ZERO Mode
Designed to detect every type of metal; use
ZERO mode to find all metal items or when the
material of the desired object is unknown. All 12
discrimination pixels are switched on and High-Res
Iron Discrimination is set to 0 (zero)—indicating that
no metal targets have been eliminated.
Switch to the ZERO Mode to aid in locating a
target when its signal is inconsistent. Such signals
could mean the target is made of iron or a trash
target is close to a good target.
AT Pro International™
• COINS Mode
Designed to find most types of coins, jewelry, etc.,
while eliminating trash items such as iron and foil.
High-Res Iron Discrimination level has been preset
to 35 to exclude most iron targets. In addition,
one pixel of foil has been excluded. Be aware that
most pulltabs and pieces of tabs have not been
eliminated from detection as these trash items have
conductivities similar to small coins and jewelry.
This mode can be customized by the operator and
the AT Pro will retain the changes when the detector
is switched off. The factory preset for the CUSTOM
Mode is the same as the ZERO Mode (see previous
page). Begin with this discrimination pattern and
then use IRON DISC and NOTCH DISC pushbuttons
to customize the discrimination settings.
Zero, Coins or Custom have the same discrimination
patterns as in STD Mode. In PRO Mode, however, the AT Pro
utilizes its Pro Audio functions—including Proportional Audio
and Tone Roll Audio—to offer more target information.
The Pro Mode audio provides more target information and
faster recovery speed for separating adjacent targets. This
is especially important in areas where good targets may be
scattered amongst iron trash.
Pro Mode audio by its nature creates more audible chatter
than Standard Mode. This is normal because of the additional
sensitivity of Pro Mode. The audio depth can exceed Target ID
depth in Pro Mode so it is possible to hear deep targets that
do not register a Target ID.
Proportional Audio (Pro Mode)
Proportional audio response means that the loudness
of the target's response is proportional to a target's signal
strength. This allows the user to hear subtle changes in a
target’s response. Proportional audio response also allows
the user to better judge a target’s size, shape and depth
and has the additional benefit of faster recovery time for
separating adjacent targets.
Note: Changes made to the ZERO or COINS modes
will not be retained after the detector is switched
off. (For information on the use of IRON DISC and NOTCH
DISC, see pages 22–26.)
14 Garrett Metal Detectors
AT Pro International™
Audio Target Response Comparison: Standard vs Pro Mode
Adjacent Targets Comparison: Standard vs Pro Mode
Shallow coin
Deep coin
Notice the differences in Standard binary audio versus PRO audio in the two
target scenarios above. The binary audio gives a solid, consistent beep for
both the shallow and the deep coin. In contrast, PRO Mode's proportional
audio provides a stronger signal for the shallow coin and a softer signal for
the deeper coin. The actual profile, or signature, of the target’s response is
heard, thereby providing more information.
16 Garrett Metal Detectors
Adjacent targets
These two adjacent coins would produce one strong signal while in STD Mode.
In PRO Mode, the proportional audio provides two peaks of audio response to
allow the user to identify multiple targets.
AT Pro International™
Tone Roll Audio (Pro Mode)
This feature of Pro Mode provides the user with more
audible target information to help identify targets, particularly
flat iron objects, such as bottle caps and washers. Standard
Mode audio produces a single tone based upon the target’s
strongest signal. For flat iron objects, this single tone is often
the same as a good target. Tone Roll Audio, however, 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.
Tone ID Comparison: Standard vs Pro Mode
Target ID Legend
Target ID Cursor
(Upper Scale)
Pattern (Lower Scale)
Target ID Legend—Works in conjunction with the Target ID
Cursor to indicate a target's probable identity. Ferrous (iron)
targets will indicate on the left half, non-ferrous targets that
are thin or have low conductivity will indicate in the middle,
and thick or high conductivity targets (e.g. thick silver) will
indicate at the right.
Bottle cap
Target ID Cursor (Upper Scale)—The Target ID cursor, in
conjunction with the Target ID Legend, indicates the probable
identity of a detected target. The upper scale consists of
twenty (20) graphic segments for Target ID.
While in STD Mode, bottle caps, steel washers and other flat iron objects
often sound like good targets, producing a high tone response. This is
because the bottle cap’s shape and flat surface resembles a coin which
can trick the detector. In PRO Mode, however, the bottle cap will produce a
very distinctive response with multiple tones. 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.
18 Garrett Metal Detectors
Lower Scale—The lower scale, or Notch Discrimination
Scale, continually indicates the discrimination pattern. The AT
Pro will produce an audible target response for the pixels that
are switched on, and no audible response for those that have
been switched off. The Target ID Cursor will always indicate
all targets.
The discrimination pattern can be adjusted (as described
in the "Discrimination" section).
AT Pro International™
Target ID
The AT Pro’s Digital Target ID system provides a specific
target value to help identify targets more precisely. Targets
are identified on the LCD by number, with items near 1 being
the most ferrous. The most conductive targets (such as thick
silver) register closer to to 99.
The Digital Target ID is a more precise version of the
Target ID Cursor shown in the Upper Scale. Each Target ID
Cursor has a width of 5 digital points. For example, a Digital
Target ID of 73 will light the cursor from 70 to 75.
This system, when used in conjunction with the audio
target signals, provides you with more information. The
sample chart on the following page provides Digital Target ID
ranges of some commonly found items.
It is important to note that while operating in the PRO
Mode, the Pro Audio depth can exceed Target ID depth (i.e.
faint targets at depth can be heard without providing any
Target ID).
20 Garrett Metal Detectors
Note: Target values can vary based on the orientation of the target in the
ground, amount of ground mineralization, etc. It is important to practice in
the field to learn how these factors can affect Target ID.
The Tone ID feature produces three distinct audible tones
based on a target’s metal type and conductivity:
Ferrous targets such as nails, iron,
steel, etc.
Medium-Tone: Small, thin targets that are non-ferrous,
such as small jewelry, foil, and some very
thin, hammered coins.
High/Bell Tone:Non-ferrous targets with medium to high
conductivity, including most coins and
jewelry. Note: PRO Mode produces a high
tone; STD Mode produces a bell tone.
AT Pro International™
Example: Manual Modification of Notch Discrimination Pattern
Notch Discrimination—The AT Pro's NOTCH DISC
pushbuttons are used in conjunction with the ELIM pushbutton
to eliminate trash objects from detection such as foil or pulltabs.
Use the NOTCH DISC buttons to position the Target ID Cursor above the pixel
you wish to eliminate (see above illustration). Use the ELIM pushbutton to
delete this pixel from the Lower Scale (see below). This item is now rejected.
The AT Pro has 12 pixels or "notches" of discrimination (in
addition to the 40 points of High-Res Iron Discrimination).
Any combination of these pixels can be switched on or off
based upon your preference. There are two primary methods
for modifying the Notch Discrimination Pattern to reject a
specific type of trash or unwanted item. The first method uses the NOTCH DISC and ELIM
pushbuttons (seen above) to manually modify the Lower
Scale's Notch Discrimination pattern.
Use the (+) or (-) NOTCH DISC pushbuttons to move the
Target ID cursor to the left or right. Next, press the ELIM
pushbutton to eliminate or activate the pixel located on
the Lower Scale, directly below the Target ID cursor. (See
illustrations on next page.)
22 Garrett Metal Detectors
The second method of modifying the Notch Discrimination
pattern involves the use of only the ELIM pushbutton. When
an unwanted target is audibly detected while hunting, simply
push the ELIM button to create a notch at that Target ID
Cursor. The next time the AT Pro encounters the same trash
item, it will not produce an audible signal.
The AT Pro's ELIM pushbutton can also be used to find
specific metal items. For example, if an earring has been
lost, scan the matching earring with the AT Pro while in the
ZERO mode. Note where the Target ID cursor appears when
the earring is scanned. Next, use the NOTCH DISC and ELIM
pushbuttons to switch off all the pixels except the one for the
Note: Depending upon how the lost earring is laying in the
ground, its Target ID may shift a little; therefore, your ability
to find it will be enhanced by turning on an additional pixel
AT Pro International™
on either side. The AT Pro is now programmed to find the
missing earring based on the conductivity of its matching
Note: The notch discrimination function can be used
to modify each Mode’s discrimination pattern. Notch
Discrimination modifications made while in CUSTOM (either
in Standard or Pro mode) will be retained when the detector
is switched OFF. However, all changes made to the Notch
Discrimination pattern while in ZERO or COINS modes will
return to the factory settings when the detector is switched
OFF and back ON again.
The examples shown below illustrate how an iron object
can often "mask" out the signal of an adjacent good
target when too much iron discrimination has been applied.
Using the AT Pro's High-Res Iron Discrimination, apply just
enough iron discrimination to reject the undesired iron nail
shown in this example. By using only a minimal amount of
iron discrimination, the detector will detect the combined
conductivity of the coin and nail together thus overcoming the
potential "masking" problem.
Illustration 1
Illustration 2
Iron Discrimination—The AT Pro features a high-resolution
iron discrimination adjustment. This additional resolution
allows more precise control of how much iron discrimination
can be applied. The level can be adjusted from 0 (no iron
discrimination) to 40 (maximum iron discrimination).
High-Resolution Iron
Discrimination Setting
IRON DISC Pushbutton
Use the (+) or (-) IRON DISC
pushbuttons to adjust the Iron
Discrimination up or down.
The small two-digit number
above the words "IRON DISC"
on the LCD indicates the iron
discrimination setting.
24 Garrett Metal Detectors
Iron targets, such as the nail shown in Illustration 1, can sometimes
mask a good target's signal. If too much iron discrimination is
applied, the good target (seen in Illustration 2) can be missed.
Read page 26 to learn how to apply the proper amount of iron
discrimination to eliminate the nail shown in Illustration 1 and still
detect the good target shown in Illustration 2.
AT Pro International™
Example: Detecting Targets in Trash with High-Res Iron Discrimination
In the illustration above, the AT Pro is operating with an IRON DISC setting of
20. The nail seen in Illustration 1 (on page 25) registers from 10 to 25 on the
Digital Target ID scale. To eliminate the nail from detection, increase the iron
discrimination level to 25 using the IRON DISC (+) pushbutton.
Iron Audio
In Illustration 2, the same iron nail is laying above a good coin target. Since
the Iron discrimination level is set to 25, the nail by itself would not be
detected; however, the two objects have a combined conductivity of more
than 25.
Therefore, the good target is detected due to the combined conductivity
being higher than that of the discriminated target (nail) alone.
26 Garrett Metal Detectors
Press and release the IRON AUDIO pushbutton to switch the
Iron Audio feature ON/OFF. When this feature is on the words
"IRON AUDIO" appear on the LCD (as shown in the illustration
above). The Iron Audio feature can be used in any of the AT
Pro's six modes.
Scattered iron objects in the ground can mask good targets
and even create “ghost signals” that appear to be a good
target. Garrett’s selectable Iron Audio feature allows the user
to hear discriminated iron (normally silenced) in order to
know the whole picture and avoid being tricked into digging
an undesired target.
Iron Audio also allows adjustment of the mid-tone’s range
to include all targets above the iron discrimination setting.
The user is adjusting the cut-off between low-tone iron targets
and mid-tone targets to better distinguish good targets.
AT Pro International™
Refer to the illustrations below regarding the use of the Iron
Audio feature:
IRON AUDIO OFF: Normal division of low, mid and high tones.
IRON AUDIO OFF: With the Iron Discrimination set to 20, all targets below
20 are silent.
iron object like a bottle cap or steel washer will produce a very
distinctive Low-High-Low response.
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.
Start with the AT Pro in Standard (STD) Zero Mode and pass
the searchcoil over a bottle cap which is lying flat on the
ground. Note that the target response is consistent with the
audio of a good target.
Then, switch the detector into PRO Zero Mode and pass
the searchcoil over the bottle cap again. Note the subtle
low tones at the beginning and end of the target response,
indicating a questionable target that might be made of
iron. Finally, set IRON DISC to 35, switch on Iron Audio
and pass the coil completely over this target again. The
distinctive Low-High-Low response now indicates a target that
is unmistakably iron.
IRON AUDIO ON: Targets below 20 are now heard as a low tone and targets
above 20 will produce a mid or high tone.
When Iron Audio is on in the PRO Mode, iron targets will not
only be heard, but they will produce an even more distinctive
response with multiple tones. For example, a nail will produce
several fast low tones as the searchcoil passes over. A flat
28 Garrett Metal Detectors
AT Pro International™
(only displays on
LCD when in use)
GND BAL Setting
(only displays
while in Ground
Balance mode)
The AT Pro has eight (8) settings for sensitivity. Use the (+)
or (-) SENSITIVITY buttons to step through the eight levels,
which are continuously shown on the LCD.
Use higher sensitivity levels when searching for very
small or very deep targets. Use lower sensitivity levels in
locations where the detector is behaving erratically due to
excessive metallic trash, highly mineralized soils, saltwater
beaches, electrical interference or the presence of other
metal detectors.
30 Garrett Metal Detectors
(use with GND BAL)
GND BAL Pushbutton—Hold for Automatic Ground Balance
or use in conjunction with the NOTCH DISC pushbuttons for
Manual Ground Balance.
Detector performance can be negatively affected by ground
mineralization. The AT Pro can be ground balanced either
automatically or manually to cancel unwanted ground signals
and obtain maximum stability and target detection.
Automatic Ground Balance: Press and hold the GND BAL
pushbutton while continually "bouncing" or "pumping" the
searchcoil from 2 to 20 centimeters above the ground. When
there is a minimal audio response from the ground, release
the pushbutton and begin hunting. The ground balance value
will have been indicated in the center of the LCD. Low ground
AT Pro International™
balance values indicate conductive soil; high ground balance
values indicate ferrous soil.
Manual Ground Balance: You may want to use the Manual
Ground Balance function to ground balance slightly positive
to enhance detection of small targets or balance slightly
negative to reduce detection of "hot rocks," terra cotta and
Press and release the GND BAL pushbutton and continually
bounce (pump) the searchcoil from 2 to 20 cm above the
ground. If low tones are produced, increase the Ground
Balance setting using the (+) NOTCH DISC pushbutton. If high
tones are produced, decrease the setting using the (-) NOTCH
DISC pushbutton. Press and release the (+) or (-) NOTCH DISC
pushbuttons to make single-step adjustments, or press and
hold to make large adjustments.
Continue bouncing the coil and making adjustments until a
minimum audio response is obtained, indicating the detector
is ground balanced. The Ground Balance setting will be
indicated on the LCD.
Press and release the GND BAL pushbutton again to exit
Manual Ground Balance mode. The Ground Balance setting
will be retained when the detector is switched OFF.
Typical Ground Balance Ranges:
80–99: Highly ferrous (magnetite, ferrous oxide minerals,
black sands, hot rocks, terra cotta)
60–80: Moderately mineralized soils (red clay, brown clay,
iron-bearing clay minerals, etc.)
20–60: Likely an iron object
0–20: Highly conductive, non-ferrous minerals such as
32 Garrett Metal Detectors
Freq Adjust
Use the PINPOINT/Freq Adj pushbutton in conjunction with
the (+) or (-) SENSITIVITY pushbuttons to adjust frequency.
The AT Pro is capable of operating at four slightly different
frequencies in order to minimize the interference caused by
electrical sources (e.g. power lines) or other metal detectors.
To adjust frequencies, hold down the PINPOINT button and
press the (+) or (-) SENSITIVITY pushbuttons to change the
frequency to find one with the least amount of interference.
The frequency setting (F1–F4) will be indicated on the LCD.
Release the PINPOINT button when finished.
Note: Frequency adjustments are small and therefore do
not affect target detection capabilities.
AT Pro International™
Upper Scale indicates
signal strength
Press and hold the Pinpoint pushbutton to determine
the exact location of a target. To use the pinpoint function,
position the searchcoil to the side of the target's suspected
location at a fixed height above the ground (e.g. 2cm). Press
and hold the Pinpoint button and sweep the searchcoil over
the target area while maintaining the same fixed height
above the ground (e.g. 2cm). Sweep the searchcoil sideto-side and front-to-back in a crosshair pattern to locate
the peak signal. Note: it is recommended to maintain a
constant height during the entire Pinpointing process to
prevent ground mineralization from producing false signals
or masking the target's signal.
The bar graph on the LCD can also aid in locating the peak
signal. When pinpointing, the Upper Scale on the LCD Screen
indicates signal strength. When the greatest number of LCD
segments (increasing left to right) are shown, the center of
the searchcoil is directly over the target with the depth of a
coin-sized target shown on the depth scale. The symbol "PP"
for pinpoint is displayed on the LCD while pinpointing.
It is recommended to practice pinpointing in a test plot.
Note: The center of
detection is under
the center of the coil,
just ahead of its stem
mount. The opening
just ahead of the stem
mount can serve as
your reference point
for pinpointing.
34 Garrett Metal Detectors
center of the
28 x 22 cm DD
Coin Depth
PINPOINT Pushbutton
(Press and hold to pinpoint)
using Pinpoint
Note: For best pinpointing results, maintain a constant height
above the ground (e.g. 2cm) and ensure that the detector is
properly ground balanced.
AT Pro International™
Coin Depth Indicator—The depth of a coin, or similar sized
target, is indicated in 5cm increments. Note: targets larger
than a coin may display shallower than actual depth while
targets smaller than a coin may display deeper than actual
• Alternative pinpointing technique: DD-tip or tail. In the
standard pinpointing method described on pages 34, the
target is pinpointed beneath the center of the searchcoil.
Some detectorists using DD coils prefer to pinpoint off the tip
or tail of the searchcoil.
Image A
Image B
36 Garrett Metal Detectors
DD "tip" pinpointing technique
Press and hold the Pinpoint
pushbutton and sweep the
searchcoil side-to-side to center
the target (the point where the
strongest audio response is
heard and the maximum signal
strength is displayed on the LCD).
Then, pull the searchcoil slowly
toward you (see Image A), while
noting the target signal.
Tip for narrowing the detection area: Large targets can
produce wide signals while pinpointing, making it difficult
to precisely locate the target's center. To help pinpoint, the
detector can be retuned to the target to narrow the detection
field as follows.
While holding down the Pinpoint pushbutton, move the
coil toward the target until the LCD just reaches a full-scale
response. Then, quickly release and depress the Pinpoint
button again to retune the detector and narrow its detection
field. Continue moving the searchcoil toward the target to
find its central peak response. If needed, repeat the retune
process to further narrow the target's response.
A quality hand-held pinpointer such as Garrett's ProPointer is a recommended accessory item to speed the target
recovery process and to aid in locating secondary targets.
Once the target signal drops off
(both audibly and on the LCD
meter), shallow targets should
be located immediately in front
of the searchcoil's tip (see Image
B). Deep targets will be under or
just inside your searchcoil's tip.
This is because the conical shape
of the searchcoil's detection field
begins bending in slightly as the
depth increases.
AT Pro International™
You can reverse this pinpointing technique to pinpoint off
the DD coil's tail; in this case, push the coil away from you.
The audio and LCD meter will place the target just off the
searchcoil's tail.
• Alternative pinpointing technique: DD-wiggle. Quickly
locate targets without using the Pinpoint button as follows.
Continuously swing the searchcoil side-to-side using fast,
narrow swings of 5–10cm (i.e. wiggle). While continuing
this side-to-side wiggle, slowly move the searchcoil sideways
toward the target's suspected position until the audio response
produces a consistent, symmetric beat. This indicates the
lateral left-to-right position of the target. Then locate the
target's front-to-back position by rotating around 90° and
repeating the same process.
Tip: Practice any or all of these various pinpointing options in
your test plot. Choose the technique that works best for you.
As you improve your pinpointing accuracy, you will dig smaller
holes and increase your productive hunting time.
• Begin hunting in STD Mode, then switch to PRO Mode after
you have become more experienced.
• If you are new to metal detecting, start searching in areas
with sandy and loose soil to make it easier to learn how to
use your metal detector, pinpoint and dig targets.
•Keep your searchcoil at a constant height of 2 to 3 cm
above and parallel to the ground at all times for best
detection results. Do not lift or tilt the coil at the end of
38 Garrett Metal Detectors
AT Pro International™
•Walk slowly as you scan your searchcoil in a straight line
from side to side at a speed of about 1 meter per second.
Advance the searchcoil about half the length of the
searchcoil at the end of each sweep.
Overlap Swing
by 14 cm
Overlap Swing
by 14 cm
Walk slowly
to allow
of the
Scan side
to side
1m per
40 Garrett Metal Detectors
In order to fully search an area, overlap the swings of your searchcoil by
half the length of the coil (about 14 cm). Sweep the searchcoil in a straight
line or with a slight arc at a sweep speed of about 1m/sec.
Tips for saltwater use: Hunting in a saltwater environment
is challenging for any Continous Wave (VLF) metal detector.
Saltwater is conductive and produces signals similar to foil.
Although the AT Pro is not specifically designed for saltwater
use, it can be used in this environment.
Proper ground balance is the most important step for
stable saltwater operation. To achieve stable operation:
• First, Ground Balance the detector to the area that will
be hunted (see pages 31–32). Saltwater beaches
typically Ground Balance between 0 and 20.
• If necessary, reduce the Sensitivity until the signals
become stable.
• Swing the searchcoil flat and at a constant height.
Do not bounce the coil or lift the coil at end of swings.
• Swing the searchcoil parallel to the water's edge.
AT Pro International™
• The detector will be less stable in shallow, breaking surf
where the searchcoil is in and out of the saltwater.
In this area the detector is encountering a constantly
changing environment produced by the surf, making it
difficult for the detector to stabilize.
To improve stability, negatively bias the ground
balance by several points. To do so, simply press
and release the Ground Balance button and
use the (-) NOTCH DISC pushbutton to manually reduce
the ground balance setting. For example, if the Ground
Balance number was 11, reduce the Ground
Balance number to 7 or 8. Introduce only
enough negative bias to achieve sufficiently stable
operation. Reduce the detector's Sensitivity as needed.
Note: While some background chatter may remain, the
more definitive response of a target can be recognized.
• If necessary, notch out the first pixel under Foil. It is
important to note that by notching out this pixel,
detection of some small jewelry items will be reduced.
Tips for locating targets amongst terra cotta/hot rocks:
Magnetic minerals such as hot rocks and terra cotta can
mask the presence of good targets. In order to detect a good
target, first ground balance the AT Pro to the terra cotta or hot
rocks that are present. Be aware, however, that the combined
Target ID might be very low (e.g. a bronze coin and terra
cotta together may register between 10 and 15 on the Digital
Target ID). Therefore, Iron Discrimination levels must be
reduced in order to ensure detection of good targets covered
by the terra cotta. The Iron Audio feature can also be used
so that all targets above the point of discrimination produce
either a medium or high tone (i.e. "good" targets).
42 Garrett Metal Detectors
• Isolating adjacent targets. The narrow detection field
of the AT Pro's DD searchcoil allows better separation of
adjacent targets versus a similar size concentric searchcoil.
Use narrow swings of the searchcoil in trashy areas to isolate
good targets amongst the trash.
• Swing your searchcoil parallel to plow lines and the
water's edge. This will minimize the negative effects caused
by uneven ground in plowed fields and varying amounts
of moisture near the water. Do not swing the searchcoil
perpendicular to plow lines and the water's edge, as this may
produce abrupt changes in ground response that can reduce
the detector's performance.
AT Pro International™
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:
•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 8 to 10 cm. 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.
44 Garrett Metal Detectors
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 5 cm
to 10 cm to 15 cm. 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
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
AT Pro International™
at a distance of 8 to 10 cm. Note that the bottle cap's flat
surface gives a Digital Target ID reading in the 75–85 range
and produces the high tone of a "good" target.
Next, switch to PRO Mode and pass the bottle cap across
the coil again and notice the different audio. The clean sound
heard in STD has been replaced with a mixed, chirping tone
that has subtle low tones at the beginning and end, indicating
a possible junk target. Pass a conductive, coin-sized target
across the coil and note its clean high tone in comparison to
that of the bottle cap.
Finally, remain in PRO Mode and set IRON DISC to 35
and switch on the Iron Audio feature. Pass the bottle cap
completely across the coil again and note the high-tone chirp
that is flanked by distinctive low tones on either side. Again,
use a conductive, coin-sized target to compare its signature
to that of a bottle cap in this PRO Mode Iron Audio setting.
The bottle cap makes a response that is unmistakably iron.
Final tip: Record the results of your bench tests and refer
to them when hunting in the field. Knowledge of the PRO
Mode and the Iron Audio feature can reduce the amount of
trash targets that are dug.
The AT Pro can be immersed in water to a 3-meter depth
(maximum) to search in and along shorelines, rivers, piers,
docks or swimming holes. Use of the AT Pro at depths
exceeding 3 meters can cause leaks and damage the
detector. Use of the AT Pro beyond the recommended depth
will void the manufacturer's warranty. For use in saltwater,
see tips on pages 41–42.
The AT Pro is shipped with standard land-use headphones.
These can be used for searching along waterways, but may
not be submerged. For submersion, optional waterproof
headphones (available from Garrett) must be used.
Waterproof headphones (sold separately) must be used if the AT Pro is fully
immersed in water. The standard land-use headphones included with the
detector are not waterproof.
46 Garrett Metal Detectors
AT Pro International™
Battery Level
Battery Replacement—The AT Pro is operating with fresh
or fully charged batteries when 4 illuminated bars on the
Battery Level Indicator (see above) are displayed. The
detector will maintain full performance until the batteries
need to be replaced. Replace batteries when there is only
one segment remaining. NiMH rechargeable batteries may
be used. Expect 20 to 40 hours of operation depending on
battery type and quality.
Access and replace the batteries by rotating the battery
cover housing one-quarter turn counterclockwise. Pull and
remove the cap to slide battery holder out. Remove batteries
when the AT Pro will be stored for longer than 30 days.
The AT Pro is a rugged machine, designed for outdoor
use in all environments. However, as with all electronic
equipment, there are some simple ways to care for the
detector to maintain its high performance.
• Avoid extreme temperatures as much as possible, such
as storing the detector in an automobile trunk during the
summer or outdoors in sub-freezing weather.
• Keep the detector clean. Wipe the control housing with a
damp cloth when necessary.
Remove the battery
cover by rotating
the cover onequarter turn in a
direction. Grasp
the cap by top and
bottom and pull it
straight back. Slide
the battery tray
out to replace the
48 Garrett Metal Detectors
• Disassemble the stem, and wipe it and the searchcoil clean
with a damp cloth.
• When storing for longer than one month, remove the
batteries from the detector.
• It is best to use quality alkaline batteries. When changing
batteries, be sure to replace with all new batteries for
optimum performance.
• Replace protective cover on the connector when not using
AT Pro International™
No power
1. Ensure batteries are installed in the correct position.
2. Replace all old batteries with all new batteries.
Erratic sounds or
target ID cursor
1. Ensure your searchcoil is securely connected with the
O-ring properly sealed and that the coil cable is snugly
wound around the stem.
2. If using the detector indoors, be aware that excessive
amounts of electrical interference exists, plus excessive
amounts of metal can be found in floors and walls.
3. Determine if you are close to other metal detectors or other
metal structures such as electrical power lines, wire fences,
benches, etc.
4. Adjust frequency.
5. Reduce your sensitivity setting.
Intermittent Signals
Intermittent signals typically mean you’ve found a deeply
buried target or one that is positioned at a difficult angle for
your detector to read. Scan from different directions to help
define the signal. In the case of multiple targets switch to the
ZERO Mode or press the pinpoint button to precisely locate
all targets. In trashy areas, use the Super Sniper™ searchcoil.
(NOTE: Iron targets may cause Intermittent Signals. You can
identify iron targets in ZERO Mode or with the Iron Audio
I’m not finding
specific targets
Ensure you are using the correct mode for the type hunting
you are doing. If specifically hunting for coins, COINS mode
should be your best choice to eliminate other undesirable
targets. You may also use the ZERO mode, which detects all
metal targets to ensure desired targets are detected.
Target ID Cursor
If your Target ID Cursor bounces erratically, chances are
you’ve found an iron target. However, a Target ID Cursor may
bounce if a good target (such as a coin) is not parallel to the
searchcoil (e.g. on edge). It may also bounce if there is one
or multiple “junk” targets laying next to the good target. Scan
from different directions until your Target ID Cursor becomes
more stable.
NOTE: Large, flat pieces of iron—depending on their
orientation in the ground—can read as a good target or can
cause erratic Target ID Cursor movement. Use Iron Audio
feature to help identify iron targets.
50 Garrett Metal Detectors
The following is a Code of Ethics that many treasure hunt
clubs endorse and hobbyists follow to preserve our exciting
hobby of metal detecting. We encourage you to do the same:
• I will respect private and public property, all historical and
archaeological sites and will do no metal detecting on
these lands without proper permission.
•I will keep informed on and obey all local and national
European legislation relating to the discovery and reporting
of found treasures.
• I will aid law enforcement officials whenever possible.
•I will cause no willful damage to property of any kind,
including fences, signs and buildings.
• I will always fill the holes I dig.
• I will not destroy property, buildings or the remains of
deserted structures.
•I will not leave litter or other discarded junk items lying
• I will carry all rubbish and dug targets with me when I leave
each search area.
• I will observe the Golden Rule, using good outdoor manners
and conducting myself at all times in a manner which will
add to the stature and public image of all people engaged
in the field of metal detection.
AT Pro International™
When searching for treasure with your Garrett detector,
observe these precautions:
• Never trespass or hunt on private property without
•Avoid areas where pipelines or electric lines may be
• National and state parks / monuments, etc are absolutely
• Deepseeking detectors can detect concealed pipes, wiring
and other potentially dangerous material. When those are
located, the proper authorities should be notified.
•Do not hunt in a military zone where bombs or other
explosives may be buried.
•Do not disturb any pipeline, particularly if it could be
carrying flammable gas or liquid.
•Use reasonable caution in digging toward any target,
particularly in areas where you are uncertain of the ground
•If you are unsure about using your metal detector in any
area, always seek permission from the proper authorities.
52 Garrett Metal Detectors
Your AT Pro detector is warranted for 24 months, limited
parts and labor, but does not cover damage caused by
alteration, modification, neglect, accident or misuse. Use of
the AT Pro at submerged depths exceeding 3 meters will void
this warranty.
In the event you encounter problems with your AT Pro
detector please read through this Owner’s Manual carefully to
ensure the detector is not inoperable due to misadjustments.
Press and hold the power pushbutton for 5 seconds to return
to the factory settings.
You should also make certain you have:
1. Checked your batteries, switches and connectors. Weak
batteries are the most common cause of detector problems.
2. Contacted your dealer for help, particularly if you are not
familiar with the AT Pro detector.
In the event that repairs or warranty service are necessary
for your AT Pro, contact the local retail outlet where your
detector was purchased. To avoid excessive shipping and
import charges, do not attempt to return a Garrett product to
the factory in the United States.
Information on international warranty/repair needs can be
found on the Garrett website: www.garrett.com. Click on the
Hobby Division and then the Technical Support page for more
AT Pro International™
11.5cm Super Sniper™ Searchcoil—
28 cm. DD Searchcoil Cover—
Part No. 1606600
Protect the searchcoil's surface from
scratching and chipping during use.
Part No. 2222500
Use when searching for small, shallow
targets or in trashy or tight places.
23 cm. PROformance Concentric Searchcoil—
Part No. 2222600
Smaller and lighter than the AT Pro's
standard DD coil, this waterproof
searchcoil offers excellent depth
for medium-sized targets in less
mineralized soils.
30.5 cm. PROformance Concentric Searchcoil—
Part No. 2222700
This larger size concentric searchcoil
is waterproof and offers excellent
depth for larger targets in less
mineralized soils.
Garrett PRO-POINTER® Pinpointing Detector—
Part No. 1166000
The PRO-POINTER combines performance with sleek design to
assist in pinpointing hard-to-find targets. Includes proportional
audio/vibration pulse rate target indicators and 360° side scan
detection area. Water resistant with LED light for low light uses.
Includes woven belt holster and 9-volt battery.
To see Garrett's complete collection of metal detector accessories,
please visit www.garrett.com and view products within our Hobby
Additional searchcoils, recovery tools, headphones, carrying bags,
searchcoil covers, Garrett caps and Garrett shirts are available for
all detecting accessory needs.
Waterproof Headphones—
Part No. 2202100
Required when the entire headphone
set will be immersed in water.
54 Garrett Metal Detectors
AT Pro International™
Also available—pocket size treasurehunting field guides written by
Charles Garrett. Collect them all!
RAM Books, a division of Garrett Metal Detectors, publishes
new titles each year related to treasure hunting, gold prospecting, coin hunting and relic recovery.
This edition includes the author's personal
experiences of hunting in Europe, plus tips
and techniques. 76 pages. PN 1546200
European Metal
Detecting Guide
Highlights include:
• Hundreds of full-color photographs
• 5.5” x 8.5” size
Author/master treasure hunter
• 324 pages, soft cover
Part No. 1562100
• Field tips from dozens of European
metal detectorists
• Explanation of detector and
searchcoil technology
• Illustrations of proper detector
• European treasure laws information
Ideal reading for new detectorists!
(Available in English
language only)
Visit RAM Books on
www.garrett.com for
future releases.
56 Garrett Metal Detectors
AT Pro International™
European Metal Detecting Guide
Preview of Pages
Dozens of
pages of fullcolor treasure
photos with
descriptions of
the items’ age
or value.
Photo exposes
from the field,
such as this
French rally
experience. 
 Proper basic
search techniques
with illustrations.
Go to www.garrett.com and visit the Hobby Division. An order form
is available on our site which can be printed and mailed with your
requested titles and payment.
58 Garrett Metal Detectors
1881 W. State Street
Garland, Texas 75042
Toll Free: 800.527.4011
Tel: 972.494.6151
Fax: 972.494.1881
Email: sales@garrett.com
© 2012 Garrett Electronics, Inc.
PN 1533300.C.1012
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