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GSM19 Series Magnetometers - Version 7
GEM Systems, Inc. Advanced Magnetometers
For more technical information, visit www.gemsys.ca
The GSM-19 is a secondary standard for measurement of the Earth’s magnetic field with 0.01 nT
resolution, and 0.2 nT absolute accuracy over its full temperature range. Some of the system
features include:
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Microprocessor control with large memory storage capabilities (up to 32 Mbytes).
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Synchronization of and held and base station units with automatic corrections for diurnal
variations of magnetic field.
•
Access to results in serial form (RS-232-C interface) for collection by data acquisition systems,
terminals or computers.
•
On-line Real Time Transmission (RTT) and post-operation transfers.
•
Gradiometer mode with strict control of measuring intervals and concurrent measurement of
two magnetic fields. The result is a high quality reading, independent of diurnal variations of
magnetic field.
•
Option VLF sensor for combined magnetometer/gradiometer-VLF measurement.
The GSM-19 Series of magnetometers includes several models, each with different features and
options. In addition, each mode and option can be used in different ways resulting in a variety of
combinations. The purpose of this manual is to introduce the most important modes, features and
options. After understanding these, it is easier to see how they combine with the others.
If your system has a feature that is not described here, please contact us. As well, we welcome
suggestions about ways in which we can enhance this manual based on your experiences.
*Overhauser Effect (An exclusive feature of GEM Systems Magnetometers)
In contrast to a standard proton magnetometer sensor that uses a proton-rich liquid, an
Overhauser Effect sensor has a free radical added. This free radical ensures the presence of free,
unbound electrons that couple with protons, producing a two-spin system. A strong RF magnetic
field is used to disturb the electron-proton coupling. By saturating free electron resonance lines,
the polarization of protons in the sensor liquid is greatly increased. The Overhauser effect offers a
more powerful method of proton polarization than standard DC polarization (i.e. stronger signals
are achieved from smaller sensors, and with less power.)