What Do The Ground Balance Numbers Mean?

[mcjtom]

Would at least these general statements be roughly correct?

Whether measuring the response phase change in a single frequency or comparing the responses in different frequencies in MF (and also disregarding how such GB scale and its 'zero' or default are implemented in a particular detector), the ground balance objective is to filter out (ignore) the slow-changing responses caused by moving the coil over the ground minerals devoid of valid, smaller/weaker, targets. 

Rather than targeting all slow-changing signals, the filter tries to decrease only those on the ferrous-conductive 'ID' scale that the particular mixture of minerals in the ground is likely to produce (i.e. preventing unnecessary removal of slow-changing signals in the range outside of the minerals-mixture), but it needs to be shown (set to) what range it should be.

Pumping (or even sweeping) the coil over given soil simulates such slow-changing responses and allows the machine to detect the ferrous/conductive nature of the signal due to the ground in order to subsequently aim the filter (automatically or manually) at the most consequential slow-changing signal range to be decreased by the filter and thus best quiet the machine on this ground type.

If the ground signal increases when moving the coil towards the ground, the machine GB (the particular range of 'IDs' for slow-changing signals set to be filtered) is off and the filter range is incorrectly set too much towards removing slow-changing ground signals in the ferrous range, best represented by magnetite (at the expense of insufficiently filtering the true ground response which may be in the more conductive range, i.e. towards the salt). 

If the coil 'sings' when being moved away from the ground, it indicates that the machine GB is also not set optimally, but this time it is trying to filter the higher conductive range (closer to salt) whereas the actual soil response may be in the magnetite range and remain unfiltered (thus producing the false signal caused by spacial changes in soil composition or changing the coil-to-ground distance).

[Off Grid]

Thanks to everyone for this discussion, I learned a lot. Now I know why my Gold Bug 2 balances at 6-7 in ground that I know has very, very low magnetite.

[EL NINO77]

EQUINOX's Ground Balance for highly concentrated magnetite / magnetic mineralization / will show you the value of Ground balance 2-3 .... what is right with the assumption .. that the factory setting of GB at Equinox is 0..portionably close to calibration to ferrite / gb similar to in magnetite / ...

the terrain of the  gold forest has a value of GB= 3...

  with GB Equinox for Hematite / iron mineralization / you can get very different values= 15 GB  ... because it is a iron mineralization ..

 the red terrains of the Pyrenees may have high values of GB 60_64...

  On the other hand ... very light sandy terrain can show a value ofGB 8  ... and higher... ... 20-30GB.. 

according to me, Equinox takes into account several factors when measuring GB, except for Phase Terrain ...

 

 

 

[Steve Herschbach]

On 2/5/2022 at 5:19 AM, PimentoUK said:

I believe that ground with strong magnetite will still have electrically conductive minerals in it, it's just that the magnetite dominates the response to a detector, and whether it's also medium mineralised or hardly any minerals, or wet, or bone dry, has very little effect on the phase angle, it's going to be pretty close to Zero degrees, which would nominally be '00' on the Eqx, and '90' on the Fisher F75.

[[ mathematically, it's Vector addition:

There is a 'Zero Degrees' signal caused by the microscopic iron / rust / magnetite etc.

And a '90 Degrees' signal caused by minerals making up the ground, that conduct electricity, particularly when wet.

These two add together like vectors. The total strength would be calculated using the Pythagoras equation:

(Total strength)^2 = (Zero degrees)^2 + (90 degrees)^2

And the resulting Phase angle = arctan (90 degrees / Zero degrees )

The phase angle is the figure that is manipulated heavily to end up presented as 'Ground Balance', whether it goes 0 >99, or 90 to 0 , or anything else. ]]

A wonderfully detailed, but concise, explanation of why a ground balance number is geared more to reflect the TYPE of ground, not the AMOUNT or INTENSITY of the ground. For that we need the Fe3O4 meter. I should know better.