Very Low Frequency
Electromagnetics
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VLF surveying relies on radio
signals that are broadcast from navigation stations around the world. The
principle is that these signals are deflected in certain ways when they
pass through conductive ore or water-filled vertical-to-sub-vertial
fractures in the earth. By monitoring these deflections, the position
and, potentially, size of the target can be determined. |
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VLF
- Robust Options for Resource and Water Exploration
The VLF instrument is the electromagnetic system of choice for
professionals who require:
High sensitivity
Low weight and power consumption
Robustness
Omni-directional
capability
GEM is a leading
commercial provider of VLF systems and has supplied
systems for both mineral and water exploration.
The VLF option is built in
to a GEM console. It comprises a small white box that can be attached to
the backpack assembly. VLF data can be plotted on the graphic display in
real time. In addition, the Walking mode option allows magnetic and VLF
surveys to be conducted simultaneously and with very little user
intervention.
Data values acquired
include:
Time, as hhmmss.s
Line number and direction
Station number and direction
Uncorrected magnetic field (nT)
Corrected magnetic field (nT)
Slope (degrees)
VLF station frequency
ip - vertical in phase component (%)
op - vertical out of phase component (%)
x - horizontal amplitude
y - horizontal amplitude
VLF total field strength (pT)
VLF
Benefits
Some of the key benefits of GEMs VLF
technology include:
Multiple frequency data acquisition with minimal effort. The
system has an automatic 3 station, progammable display and recording
capability.
Versatile station set-up. Stations between 15 and 30 kHz can be
programmed easily.
Easy operation. An automatic tilt correction option streamlines
acquisition of data in the field.
Simultaneous acquisition of magnetic and VLF data. Overhauser magnetometers operate in either
pulsed or continuous modes. With pulsed modes, the sensor can be shut
down to save power. With continuous reading magnetometers, power
consumption is still minimized as only a few watts are required to
operate the system.
For more information
For more information on Overhauser technologies, please refer to the
technical papers on this site and the
GSM-19 brochure. There are also
case histories in selected application topics that are accessible via
the Applications drop-down on GEM's homepage.
If you would like
information specific to your work, please visit our
Quotations
area and submit a Request for Quotation (select VLF option). We would be delighted to
provide you with a no-obligation quote suited to your exact needs.
GEM Advanced Magnetometers.
Our World is Magnetic.
Applications
