Garrett PD 6500i User Manual page 28

3.5.25 ALArM LeveL
Alarm level is a useful installation tool that helps you determine the lowest level of sensitivity
required to activate an alarm for a particular metal object. This information can then be used to
determine the desired level of sensitivity. Alarm Level is also very useful in evaluating
interference and noise levels. Alarm level is a "view only" menu item and is a measurement or
readout of the signal level present on the detector.
ALARM LEVEL, followed by the current alarm level reading, will appear on the LCD. The
following are examples of the use of alarm level.
Using Alarm Level to determine required sensitivity:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
After choosing the base sensitivity, press ACCESS to make another adjustment or OPERATE
to resume normal operation.
Using Alarm Level to evaluate interference:
1.
2.
3.
4.
5.
6.
© 2008 Garrett Metal Detectors
PD 6500i User MANUAL
Press the + (plus) touchpad to reset the reading. The reading should reset to greater than
190 (>200 is ideal); otherwise, interference is present.
Ensure that you are metal free.
Hold the selected test object at the center of your waist.
Walk through the metal detector.
Note the new alarm level reading.
Change the test object's location and/or orientation.
Repeat steps one through six several times with the target in various locations until
you are satisfied that you've performed enough tests.
Choose the highest reading produced by the test object.
Return to the base sensitivity menu item and enter the alarm level reading that you
chose in Step 8 as the base sensitivity.
Confirm the new base sensitivity setting is appropriate by testing the selected test
object at varying locations and orientations within the walk-through (alarms should
occur with each pass), particularly in critical locations and orientations where you
suspect detection is most difficult.
If alarms do not occur in the critical locations, preferably increase the zone boost for
that location, or increase base sensitivity.
Ensure the detector is not moving and there is no movement of nearby metal or
people.
Gently press the + (plus) touchpad to reset the Alarm Level reading.
Observe the Alarm Level reading for several seconds.
Repeat steps 2 and 3 several times to determine the background interference level.
It is desired that the Alarm Level numbers remain very close to or greater than 200,
indicating small levels of interference.
If necessary, try switching off nearby equipment or moving the detector and repeating
steps 2 and 3 in order to determine the source and/or location of interference.
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