Roger,
My consulting company recently looked at various fluxgate magnetometer
sensors with the specific goal of coming up with a cost-reduced design for
the sensor itself. The attached file describes plans for a family of such
inexpensive flux-gate sensors. So, if you are inclined to build things
yourself, I believe the attached file will help you build the sensor
itself. If you are wish to go further and build a gradiometer using two
such fluxgates, I can send you the schematic; please read the attached file
for more information.
I also have a suggestion for increasing the probability of detecting
underground ferromagnetic objects. As you know, most ferromagnetic
substances do not sufficiently disturb the ambient field for reliable
detection under all circumstances. The idea is to magnetize them before
detection, so that they can be detected by their own field, rather than by
their redirection of the ambient field. Therefore, you zap the test area
with a strong magnetic field and then you scan it with a magnetometer in
the hope that the target has been magnetized and has a field of its own.
Obviously, you DO NOT do this in an area containing land mines or other
electronics, but the inducing field can be generated by something as simple
as a large coil of wire momentarily connected to a car battery.
This method is more suitable for finding archeological artifacts
("treasure"), than for what you have in mind, but perhaps other members of
this mailing list have done it, and can offer advice on how best to use it.
Sincerely,
Peter Vizmuller
President,
RHR Laboratories
www.rhrlaboratories.com
Attachments:
Fluxgate.pdf
My consulting company recently looked at various fluxgate magnetometer
sensors with the specific goal of coming up with a cost-reduced design for
the sensor itself. The attached file describes plans for a family of such
inexpensive flux-gate sensors. So, if you are inclined to build things
yourself, I believe the attached file will help you build the sensor
itself. If you are wish to go further and build a gradiometer using two
such fluxgates, I can send you the schematic; please read the attached file
for more information.
I also have a suggestion for increasing the probability of detecting
underground ferromagnetic objects. As you know, most ferromagnetic
substances do not sufficiently disturb the ambient field for reliable
detection under all circumstances. The idea is to magnetize them before
detection, so that they can be detected by their own field, rather than by
their redirection of the ambient field. Therefore, you zap the test area
with a strong magnetic field and then you scan it with a magnetometer in
the hope that the target has been magnetized and has a field of its own.
Obviously, you DO NOT do this in an area containing land mines or other
electronics, but the inducing field can be generated by something as simple
as a large coil of wire momentarily connected to a car battery.
This method is more suitable for finding archeological artifacts
("treasure"), than for what you have in mind, but perhaps other members of
this mailing list have done it, and can offer advice on how best to use it.
Sincerely,
Peter Vizmuller
President,
RHR Laboratories
www.rhrlaboratories.com
Attachments:
Fluxgate.pdf