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Has anyone done a comparison of the mineralization readouts of various brand detectors on the same ground? I know Fisher F75 is considered a standard. I would like to be able to compare my NM Anfibio readings to other detectorist's ground conditions. F75, Deus etc. Also what GB settings others consider mild----hot ground.

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I've just downloaded the Anfibio user manual to see what they say about the mineralisation meter .... they basically say nothing. It has 5 bars, and it wouldn't surprise me if it closely followed the F75 scaling, two bars per decade, and similar scaling. However as it's a selectable freq machine, you need to consider which freq is being used, and then consider if N-M recalibrate the scaling when the user changes freq, or does it give a different reading for each freq?

And re: GB values .... GB has nothing really to do with 'hotness', though it's probably true that 'hot' ground has close to zero phase lag, hence reads '90' on an F75 ( and probably other machines with that GB scaling ).

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My guess the NM machines are just a proportional graph. The readings between my Multi Kruzer across frequencies remain the same and similar to the Gold Racer which has a % next to a graph bar and no numbers.

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Yes, the owners manual is vague on the subject. It describes Ground Mineralization by Ground Balance ranges.

Some of my hunting sites are deep sandy soil that gives at most 1 Bar on the scale and Ground Balances in the mid 50's. I know this is mild. Some other sites are red dirt over red clay and will give 3-4 Bars on the scale and Ground Balance at 68-74. I am trying to get a idea of the relative soil mineral intensity. The goal being having a gage on the effect it has on the detector's performance and learning how to adapt to the different ground conditions. I think it would be helpful to me to know my 3 Bar on the Anfibio scale is roughly equivalent to X on a F75 or Deus...  I realize Ground Balance numbers vary by manufacturer.

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10 minutes ago, kac said:

My guess the NM machines are just a proportional graph. The readings between my Multi Kruzer across frequencies remain the same and similar to the Gold Racer which has a % next to a graph bar and no numbers.

Can you correlate the readings of the Kruzer and Racer? #Bars on Kruzer to % on the Racer?

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16 hours ago, PimentoUK said:

And re: GB values .... GB has nothing really to do with 'hotness', though it's probably true that 'hot' ground has close to zero phase lag, hence reads '90' on an F75 ( and probably other machines with that GB scaling ).

Sounds like GB value has something to do with 'hotness'.  This is a topic/issue that comes up frequently -- the difference between ground phase (as measured by a Ground Balance number/value) and mineralization level.  They are different measurements.  However, suppose we collected (from around the world would be great) measurements of both quantities for hundreds of sites with the same detector type (e.g. Fisher F75 which seems to be the 'standard').  Then we make an X-Y graph/plot with one axis delineating ground phase and the other the mineralization value.  Will the plot look like someone blasted it with (tiny) shotgun pellets or would there be a correlation -- i.e. discernable pattern with the datapoints grouping in certain places on the plot?  My guess is the latter, and your example ("...'hot' ground has close to zero phase lag, hence reads '90'...") is consistent with my expectation.

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Bars are the same between the 2 machines.

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Hmmm. I did say 'Nothing really to do with hotness' ... which probably doesn't translate transatlantically.

It means: 'not much to do with hotness'. Hence my statement giving an example of one common correlation: - strong ground ,and '90' GB ( machine dependant)

So ... I'll try and explain it.

Ground signal comprises two components:

A 'Zero degrees' component, caused by the microscopic iron and rusted iron that is spread throughout the ground.

A '90 degrees' component, that's attributed to the electrically-conductive minerals ( carbonates/chlorides/sulphates etc ) dissolved in the water in the ground.

These two add together, in Vector fashion. Meaning there is one ground signal, that has a phase relationship to the detectors transmitted signal.

It's possible for the detector to measure this amplitude, and the phase. This is often done by resolving the single ground signal into its two constituents, 'zero degrees' and '90 degrees' , then doing some mathematics. The phase is ( after some manipulation ) what is presented as Ground Balance' . The strength of the 'zero degrees' signal is presented as the 'mineralisation strength'.

As examples:

*Mild ground ,typical UK stuff:

'Zero degrees' = 10 units; '90 degrees' = 2 units

Phase is 11.3 degrees, GB display reads '70'.

Mineral bargraph reads "1 bar, 0.03% magnetite"

-----------

*Tennessee devil dirt:

'Zero degrees' = 1000 units; '90 degrees' = 2 units

Phase is 0.11 degrees, GB display reads '89'.

Mineral bargraph reads "5 bar, 3% magnetite"

------------

*Some weird salty ground, maybe where "Monte" lives

'Zero degrees' = 35 units, '90 degrees' = 35 units

Phase is 45 degrees, GB display reads '40' .

Mineral bargraph reads "2 bars, 0.1% magnetite"

I hope that made sense ( and I hope it's reasonably correct, I don't want Carl moaning too much ).

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6 hours ago, GB_Amateur said:

Sounds like GB value has something to do with 'hotness'.  This is a topic/issue that comes up frequently -- the difference between ground phase (as measured by a Ground Balance number/value) and mineralization level.  They are different measurements.  However, suppose we collected (from around the world would be great) measurements of both quantities for hundreds of sites with the same detector type (e.g. Fisher F75 which seems to be the 'standard').  Then we make an X-Y graph/plot with one axis delineating ground phase and the other the mineralization value.  Will the plot look like someone blasted it with (tiny) shotgun pellets or would there be a correlation -- i.e. discernable pattern with the datapoints grouping in certain places on the plot?  My guess is the latter, and your example ("...'hot' ground has close to zero phase lag, hence reads '90'...") is consistent with my expectation.

At some point in the past I read that Charles Garrett and his team actually documented ground conditions in many locations around the world. This is probably common among detector manufacturers. Would be interesting to see an accurate presentation.

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47 minutes ago, PimentoUK said:

I hope that made sense ( and I hope it's reasonably correct, I don't want Carl moaning too much ).

Makes sense to me.  Thanks for going into more detail (and especially for showing examples).  As far as figuring out whether or not Carl Moreland sees this and moans, that's way outside my pay grade.  :biggrin:

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