16A SIMPLE DETECTING EXERCISE 
DETECTOR AUDIO 17
Buried metal objects are referred to as targets. Before attempting to pinpoint or recover real targets, it is important to understand how to interpret the audio and visual signals of the detector.
A good way to become familiar with detecting is to test the detector with a range of metal objects. This exercise is a simple lesson on how the detector interprets metal objects.
Gather a collection of different metal objects, e.g. various coins, gold and silver jewellery, a nail,
Take the detector outdoors, away from known
Don’t worry if the detector is not producing a sound over the nail - this is because the detector begins in the default Pattern 1, a setting which rejects signals from common junk targets, including ferrous targets.
Note: If you are getting signals from a clear patch of ground, there could be buried metal objects. Try finding another area.
If the detector is making popping and crackling sounds and displaying numbers when the coil is not over one of the metal objects, try reducing its Sensitivity (pg. 30). Once stable, the detector will sound and display numbers only when the coil is passed over a target.
Target Response
(Metal Object Response)
This is the sound given by the detector when a target is located and not discriminated (rejected).
In Coin & Treasure Mode, a target that is highly conductive (e.g. a large silver coin) generally causes a high tone beep and ferrous targets generally cause a low tone beep.
In Prospecting Mode, a target signal will cause an abrupt change in pitch and volume of the Threshold sound.
Detections are indicated by sound only.
(Tones, pg. 38) (Sounds, pg. 46)
Threshold (Background sound)
This is the background ‘buzz’ produced by the detector, used to help distinguish between desired and undesired objects.
Blanking
When a rejected target is detected, the Threshold sound ‘blanks’ (becomes silent) indicating that a target is located underneath the coil, but has been rejected by you. Blanking is a useful way of distinguishing between desired and undesired targets.
Normal Signal
Threshold
Lay objects in a line, sufficiently spaced apart to allow the coil to pass between the objects.
Pass the coil across the objects, one
at a time, and observe the LCD and the sounds of the detector as it detects each object.
This test exercise may be used when adjusting the settings of the detector (Sensitivity, pg. 30, Volume, pg. 32, Threshold, pg. 36, Tones, pg. 38).
Ground Noise
The detector may also produce sounds when over the ground. These may not be object signals, but signals caused by mineralisation in the soil, or signals from the surrounding environment. The Ground Balance and Noise Cancel settings can be used to overcome these false signals.
(Noise Cancel, pg. 34)
(Ground Balance, pg. 40).
‘Blanking’ (No Sound)
Threshold
Highly mineralised soil may produce false signals and distract from real targets.