Detector Care And Safety - Minelab GP 3500 User Manual

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glossary of common terms – continued
Salt The presence of high salt content in the ground being searched
will have a similar but different effect on the metal detector ground
balance as does mineralization.
Salt content causes a negative (-) response rather than the
positive (+) response of laterite soils. The detector needs to
therefore use different filtering techniques to overcome this effect.
Search Coil The search coil is the circular plate which is swept across the
ground surface during detecting. It transmits electromagnetic
signals into the ground and receives the response.
Search Pattern
The search pattern is the area of ground underneath the coil
which is being scanned. Depending on the style of coil (Double D
or Monoloop) and the Coil mode being operated in (Double
D/Mono/Cancel) different coils will have a different shaped area
being covered by each sweep.
Threshold
The continuous audible level of sound emitted by the detector is
referred to as the Threshold. This threshold hum is the
background sound made as the detector operates. Threshold
can be set anywhere between silent and loud, but a soft, audible
level is normally suggested.
Target Response The electro-magnetic effect generated by the metal target under
the influence of the TX field.
Target Signal
The audio signal (or change in threshold) caused by the presence
of a metal target as the coil passes across it.
Tracking
The function of Automatic Ground Balance where the GP 3500
makes continuous adjustments to the ground balance to
compensate for changes in the mineralization of the ground.
TX
TX refers to the transmit signals or electromagnetic pulses,
sent into the ground by the coil.
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www.minelab.com

detector care and safety

– take care
The GP 3500 is a high quality electronic instrument. It has been designed for
professional gold prospecting use and the electronics circuitry is encased in a rugged
housing. Take care of your detector in the following way:
Keep the detector clean and dry. It is very important to keep all electrical connectors clean
and dry.
The control box is not waterproof, even though it has been designed to be water-resistant.
Take care to avoid it becoming wet.
The coil is water resistant and may be used in rain or wet conditions. The coil is not
waterproof. Do not immerse the coil in water.
Regularly replace such items as teardrop washers and skidplates to give long life to
your detector.
Do not expose the detector to high temperatures or leave it in the sun for longer than is
necessary. Shading will help protect it. Do not leave the detector in a closed vehicle,
especially in the sun.
The coil housing will eventually wear through if you scrub the ground with it while searching.
Use of a replaceable skid plate will help to protect your coils.
To prevent dirt entering between the coil and the skidplate, silk tape, e.g. Leukosilk
is available from chemists, may be used. The use of some other carbon based tapes,
e.g. insulation tape, may result in some loss of sensitivity.
The control box and coil should not come into contact with petrol or other oil-based liquids.
If any part of the detector comes into contact with corrosive substances, including salt or salt
water, it should be washed with fresh water.
Clean the detector with a damp cloth using a mild soap detergent.
Do not use solvents.
Do not open the control box as this will void your warranty.
All circuitry repairs should be sent back to Minelab or an Authorised repairer.
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GP 3500 page 51 GP 3500