Magnetometer LRL principle

[Funfinder]

Here some basics and how to built it:

http://www.multiupload.nl/LJFYNF9YP6


As we see there are differences in static and motion magnetometers.
Those who needs a coil in motion (and also field-mills with rotating metal disks) need special accuracy.


A moving "magneto-pistol" will measure only the field of a small stripe of the area, depending how fast it is moved from left to right. It will get different results depending how good aligned the coil is to the earth-magnetical field lines (= compass effect).


Without opamps the contrast factor output could be too low, and a very large coil could became too heavy after many hours of holding the detector by hand in front of the body.

The more different coils which are having their own analyzing circuits the better, this is another important fact.


Excluding wrong signals - also important:

The detector must not react on very low frequency or static fields or the result will be a totally mixed and messed "signal-line" that only confuses the treasure-hunter and leads to wrong search-results.


What is it that gots detected? Thats important:

This is no "signal on off detector" but it must recognise changes in the plus and minus range, in other words if the field starts to creates weaker or stronger field-strenghts which indicate distortions made by cavity, water or metal below ground.

Therefore the circuit must be able to signalize those changes into both directions, either by a row of LEDs, by sound, by an analog meter display or on a digital screen with different colours.

A digital fieldstrenght-tracking-recorder would be very practical too, for checking out if the signal-line is "real" or just a side-effect of some surrounding stronger or weaker becaming "usual field level".


btw. the overall big question is:
how to built a LRL on this principle which really works reliable

There are two different fine-tuning circuits needed, one from 10-100 uTesla to cover the complete earth and one that goes on an extra level from 0.01 to 0.1 or even better from 0.01 to 1 uTesla for the very weak treasure magnetfield-distortions.