gabbyhayes said:
My Ground Probe Readings were as follows:
VDI=-83
Phase
2.5 174.5
7.5 171.8
22.5 164.6
Strength
2.5 2.2%
7.5 2.2%
22.5 2.2%
This was with my 10DD coil and Rx. gain set to 15. I also zero'd the unit it the air prior to placing on the ground.
Based on these reading is my soil lightly or heavily mineralized?
What would extreme mineralization read?
Thanx
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'Hi there', again Gabby.
The subject of 'ground readings' on both the White's V3 series and other makes of detectors with ground monitoring indicators, is only vaguely understood by many people.
That is not surprising, because it is a very complex 'scientific' affair'.
That is because of the several variable factors involved.
(1)....The various minerals within the ground's matrix, predominantly the ferrite, and secondly, the soil's chemical contents, amount of moisture, and its pH value.
(2) ...Secondly, (but not necessarily in order of importance.) the design of the instrument involved in 'measuring' the ground's effect on the unit used.
(3)....Also, the diligence and methodology of the person performing the measurements.
(4)...The importance of the frequency involved, is ultimately reflected in the readings obtained.
The readings indicated by our detectors, are very 'rough value' indicators, and should be viewed more as an relative guide rather than an absolute measurement.
Their 'benefit' of such data, depends solely on the person's interpretation of how well he understands the 'basics of metal detecting'.
i.e. How mineralisation affects the depth and VDI accuracy of his detector.
The Whites V3 / V3i offer the best opportunity to their owner, to learn in a practical way, something about the mysteries of what is going on 'under the coil'.
Because the forum's audience may shy from the scientific aspects of what is involved and necessary to 'prove' the validity of any statements, I offer the more acceptable generalisation of the 'outcome' of what the changing figures imply.
FIRST:- Accept for the purpose of explanations, the REFERENCE figure of say,..... 90 degrees.
Let that be the phase angle for your search head when raised to waist level, IN AIR.
Now we next obtain the change in that reading when the coil is placed on the ground......The GROUND EFFECT.
If that INCREASES, then the predominant effect is caused by the presence of ferrite in the soil.
If it DECREASES, then the predominant effect is caused by the conductivity of the soil, due to moisture contents and its acidic state. ( Due to chemical and/or composite states).
So, from the 'non technical' point of view , we need only be aware of the relative variations, and then summarise them to suit our personal interpretation of what they mean.
Minus 91......low Fe mineralization
Minus 92....93....94, increasing to severe mineralisation.
DECREASING figures in to the 80's or lower, show probable increase in soil dampness and hence conductivity.
The consequences of FERRO mineralisation is to negatively mask the values of a target's conductive properties.
The consequences of Increased soil conductivity is to enhance the ground's conductivity factor, and the target's apparent signature, by an amount dependent on the target's material, shape ratio, and the frequency involved.
Depending on the absolute circumstances of target characteristics and time buried, will determine the degree of improvement in detectability.
So there are some starting points of conversation in this very intriguing subject of soil science and its relational effects on detecting.......Tex
