Why do minerals effect a detector?

[a]

When ground balancing my detector, a double beep is said to indicate balancing over metal or over ground with no minerals. As far as

I remember, I have never experienced the double beep because of lack of minerals, meaning only "rock" was present. Maybe this is because I live in Michigan, I don't know.

I understand that many hunters live in areas where the double beep is common, thus indicating hih concentrations of rock instead of minerals.

Why are minerals differant than rocks? As far as I know they are all rocks. Some are just more pure than others. Whats the differance

 

[Adrian SS]

Simply put,

Minerals that are electrically and or magnetically conductive interfere with the signal from the detector and can create a signal that will be heard in the headphones which means that iron (magnetically very conductive) and salt (electrically conductive) are the worst offenders. The Ground balance Circuits can be set to reduce the effects of these minerals while still allowing the detector to respond to precious metals.

Cheers Adrian SS

 

[a]

I understand that I should just press the ground balance button and leave the technicalities to the detector.

The reason I ask is because the instruction manual for my White Eagle detector seems to be confusing.
It states "Multinote beep indicates either an error, such as balancing over metal, or no minerals were present so a preselected GND setting was selected".

The manual seems to be saying "Multinote beep indicates the presence of conductive or magnetic material". And then the detector adjusts to compensate for it.

I read many times about detector users who have dificulty adjusting there machine because of "highly mineralized ground". This indicates to me that minerals are conductive or magnetic. This contradicts what the manual says when it groups metal with NON-MINERALS with the statement "either an error, such as balancing over metal, or no minerals were present".

I don't mean to make a mountian out of an old mole hill but I sure would like to understand.

 

[Larry (IL)]

An example of what your manual is telling you is:

On a white or light colored sand beach, there is not enough minerals for the machine to measure and ground balance to, so it will go to a pre-set value so the detector will still work. The Auto Trac feature will then take over and fine tune to the beach.

The other error is trying to ground balance over a piece of metal, again, no minerals to GB to because all it "sees" is the metal. Again Error. Squeeze the trigger for all metal mode and find a clean spot to GB to.

An example of the highly mineralized ground that people complain about is the black sand beaches, primarily on the West coast where the detector can not GB because of too much mineralization, magnetite/magnalite as well as others. That is a horse of a different color and special techniques or detectors are needed in that case to obtain a usable GB, or in other words, ground rejection, so the detector can tell a good target from the bad target, (the ground). Hope this helps some and there are others who could explain better than I, I'm sure.

 

[a]

So I think what your saying is...
1. No minerals or metal...Its like detecting nothing. There is nothing to use as a benchmark. So it gets a benchmark setting out of its program.
2. Metal...It is like interference that does not allow the detector to "think clearly" and therefore can not decide on a benchmark. So it gets a benchmark setting out of its program.
3. Minerals...It is like a mild target signal that is distributed throughout the ground and therefore can be used as a benchmark without causing interference.
4. But if the mineral is metalic like iron, copper, silver, etc it will overpower the detector as in example #2.
5. If the mineral is non-metalic (I don't know what they would be) it will cause the detector to ground balance properly as in exanple #3.

So if you do not get the multitone beep when ground balancing, that is the best condition because the detector is correctly compensating for the type of ground, which it may not always do if it has to use its pre-programmed ground balance setting.

 

[Adrian SS]

All rocks are made up of many different minerals but all minerals are not necessarily rocks.
The ONLY Mineral that a metal detector sees as mineral is magnetic iron oxide ore or magnetic black sand (drives the threshold negative)
All other NON Ferrous Metal minerals will drive the threshold positive or louder when in the zero discrimination All Metal Mode.

So when you turn your detector on as stated and the machine indicates an error, then it is telling you that there is a lump of metal close by (non Iron) that is overloading the electronics and it cannot GB correctly.or that the ground minerals are too high for the auto GB to track so the machine automatically selects a pre determined fixed level of ground rejection.. Because I do not know your type of detector very well this last bit of info may or may not be correct for your machine.

Adrian SS