A very important factor for deeper detection depth is the ground balance.
An ideal ground balance would mean that the detector only sees the targets.
It would not see the minerals in the ground. This means that one could lift the coil off the ground 6 inches or put the coil right on the ground and the output would stay 0. And this should work every where, even in the worst mineralized soils.
It would not see the earth's magnetic field. The Earth is surrounded by a magnetic field of about 0.2 to 0.5 Gauss. Near the equator, the field lines are near parallel to the surface of the ground.
In higher latitudes, the field lines are nearer 45 degrees. When we move our coil through these field lines, we generate a signal. The signal amplitude is proportional to the amount of field lines we cross and the speed at which we cross the lines.
Large coils at high speed = high amplitude signal.
What is the usual amplitude of the signal? About 1uV is the number I find in texts. Is this right? what are the parameters that produce this number?
There are other factors.
The general magnetic field lines go in the direction North-South. However, the local field lined close to the ground, may be different.
Close to the ground, the field lines may be at 90 degrees to the ground. They also may vary a lot in angle as well as field strength, within 1 or 2 meters distance. Patches of magnetic minerals and hot rocks can do that.
A perfect ground balance would have to compensate for all that, so that the output is not affected and stays at 0.
As AZIZ states, the perfect ground balance is the "Holy Grail" of metal detecting.
How can we find the perfect ground balance?
If the combined brain power of the forum works on the solution, we can find a solution.
Let's go for it!!!!!!
Suggestions?????
Should we start with looking at a few existing ground balance schemes?
Tinkerer
An ideal ground balance would mean that the detector only sees the targets.
It would not see the minerals in the ground. This means that one could lift the coil off the ground 6 inches or put the coil right on the ground and the output would stay 0. And this should work every where, even in the worst mineralized soils.
It would not see the earth's magnetic field. The Earth is surrounded by a magnetic field of about 0.2 to 0.5 Gauss. Near the equator, the field lines are near parallel to the surface of the ground.
In higher latitudes, the field lines are nearer 45 degrees. When we move our coil through these field lines, we generate a signal. The signal amplitude is proportional to the amount of field lines we cross and the speed at which we cross the lines.
Large coils at high speed = high amplitude signal.
What is the usual amplitude of the signal? About 1uV is the number I find in texts. Is this right? what are the parameters that produce this number?
There are other factors.
The general magnetic field lines go in the direction North-South. However, the local field lined close to the ground, may be different.
Close to the ground, the field lines may be at 90 degrees to the ground. They also may vary a lot in angle as well as field strength, within 1 or 2 meters distance. Patches of magnetic minerals and hot rocks can do that.
A perfect ground balance would have to compensate for all that, so that the output is not affected and stays at 0.
As AZIZ states, the perfect ground balance is the "Holy Grail" of metal detecting.
How can we find the perfect ground balance?
If the combined brain power of the forum works on the solution, we can find a solution.
Let's go for it!!!!!!
Suggestions?????
Should we start with looking at a few existing ground balance schemes?
Tinkerer
Comment