How does DEUS deal with ground mineralisation and how should I adjust the ground effects compensation in the GROUND menu, in Manual, Pumping or Tracking modes? Is it necessary to adjust?

[FORUM XP]

The different levels of soil mineralisation you encounter when prospecting can sometimes affect the performance of your detector. For example, this may be due to natural magnetic mineralisation such as iron oxide, hot rocks and magnetite, or sporadic mineralisation from sites of former human settlement (also magnetic): hearths, pottery, hot rocks, slag, etc. At the seashore this may also involve mineralisation ranging from magnetic grade (black sand) to electrical conductor grade (salt water) depending on the beach or region.

If you are an experienced detectorist you may wish to optimise your searches to achieve better penetration in some of these mineralised soils.
In magnetic ground with relatively uniform mineralisation, a setting which is adjusted according to the ground effect will improve penetration by reducing the amplitude of the ground signals sent back by the receiver circuits. This ‘adapted setting’ involves adjusting your ground balance value to the mean value of the ground being prospected, while adding 1 or point so as not to hear the ground signals as much. The Tracking and Pumping modes do this automatically if the ground conditions allow it.

Attention as the Ground Balance setting is the one requiring the most experience of the ground, we recommend that you read carefully and use the different ground balance modes advisedly, while acquiring your own experience of the ground.
By default, remain in manual mode at level 90 on inland ground and on dry beach sand.
If the ground is not mineralised there is no need to adjust your ground balance to a level other than 90: since the ground does not send back any significant spurious echo the performance will be optimal even at level 90 and you will reduce interference resulting from knocks to the coil.

4 modes are available, MANUAL/PUMPING/TRACKING/BEACH:

MANUAL mode
You can manually adjust the ground rejection levels from 60 to 95 or from 0 to 30 (Beach On mode)
90 is the default level, it is the most common level which enables you to reject all magnetic minerals found in the ground.
By reducing this figure towards 87 you will begin detecting hot rocks, and knocks to the coil may result in false signals. Even lower, between 75/85, pottery and the ground itself will begin interfering with your device.

PUMPING mode
Pumping is a semi-automatic process which allows you to adjust the ground balance in a zone that you have determined as being representative of the mean level of the ground being prospected.
Henceforth, the measured value of the ground is entered in memory and used as the new active ground balance value.
If this value is unsuitable, or if it generates too much instability, you can repeat the process in a different zone or switch to manual mode in order to modify it by, for instance, adding several extra rejection points.

Note: If a metal target is detected while you are pumping, DEUS will recognise this and display the message “Metal! Invalid Measurement”. It will then retain the previous ground balance value.
This problem is generally caused by iron being omnipresent. If this is the case then move to another location and restart the pumping mode.

Note: Similarly, if the ground you are on is not sufficiently mineralised to allow DEUS to extract an adequate value, DEUS will display Non-mineralised, Measurement impossible.
In low- or non-mineralised ground, there is no need to adjust the ground balance and you are advised to remain on 90 for greater stability.


TRACKING mode
Tracking mode is used to automatically correct the ground balance.
In this mode, DEUS repeatedly scans the ground and digitally filters the extracted signals to determine the mean value on a continual basis.

This mode may be useful in soils with relatively uniform mineralisation, and where the mineralisation varies gradually from zone to zone, which is often the case in naturally mineralised ground. In this case, DEUS automatically readjusts the ground balance according to the most recent value measured.
However, in ground where mineralisation has resulted from human presence (ancient settlements, for example) this mode may be unsuitable due to the disparity in the ground events.
Indeed, within the same sweep of just one metre, a considerable variety of ground events may be encountered, ranging from one extreme to the other (values between 70 and 90): hot rocks, brick, slag, pottery interspersed with soil that is neutral or characterised by diverse mineralisation. This may be to such an extent that any mean value would be meaningless. You must then determine an acceptable level of rejection for the ground based on your own experience of the site, your detection methods and the interference that you are prepared to tolerate.

Note: Always return to manual mode at level 90 in the event of interference, or use the pumping mode to adjust the settings over the ground zone that seems the most heavily mineralised.

BEACH ON/OFF
ON: Activates calculation of the ground balance on the zone corresponding to highly saline wet ground, so as to reduce interference caused by conducting salt water.
After selecting Beach ON, you need to adjust the ground balance manually or by pumping on the wet zone concerned, in order to cancel out the ground signal.

Note: In wet zones (salt water), it is important to sweep while keeping the coil parallel to the ground, yet not touching it.
Note: In wet zones select the Wet Beach factory programme, and start your detection by pumping over the zone concerned.