Question

[lamarc]

On a flux gate mag do you get the same depth on a object in the air as you do in the ground.

[Gypsy Heart]

http://www.treasurenet.com/f/index.p...ic,6462.0.html

These guys can probally help you out

[Carl-NC]

On a flux gate mag do you get the same depth on a object in the air as you do in the ground.

That's a good question! Mag sensors (fluxgate or not) measure magnetic field strength and magnetometers (of the gradient variety) measure the differences in magnetic fields, namely the distortion caused by iron targets. Air does not distort the Earth's magnetic field but mineralized soil can. So the answer, I think, is that mineralized soil can work to smooth out target distortions, and decrease depth.

- Carl