Proton Magnetometer - A Robust, Reliable and Affordable
Magnetic Mapping System
- High resolution
- accurate to within 0.1 gamma
- Easy operation
- automatically tunes, reads, and displays total
field at the touch of a button. Beeper sounds
when keyboard is used
- Expandable memory
- stores and accesses up to 5,700 field readings
or 12,000 base station readings
- Convenient data
recall - stored readings instantly available,
including time, date, and station number
- Automatic data
processing - download to your PC for on-line
processing, including correction for time
variations, averaging, filtering and drawing
- Versatile -
portable search and survey magnetometer,
gradiometer or base station recorder
- Works anywhere
- unaffected by orientation or environment.
Sealed, scratch-resistant keyboard is
- Easy to carry
- console weighs only 2.7kg with D-cell batteries
- Comes complete
- supplied with sensor, staff, chest harness,
batteries, carrying/shipping case, and manuals
lightweight and versatile, the G-856AX is well-suited to
a wide range of applications, including geologic mapping,
mining, fault location, archeology and magnetic search.
The Model G-856AX Proton Magnetometer automatically
measures the absolute value of the earth's magnetic field
to a resolution within 0.1 gamma. Reducing the number of
written notations required in the field, the internal
digital memory permits easy retrieval of field readings
either manually or via download to PC. Using a PC the
G-856AX can be used to produce profiles, to make
corrections for diurnal time variations, and for data
averaging or filtering. A built-in Julian clock monitors
the exact time of each reading and special function
buttons protect against accidental erasure of readings.
The G-856AX also incorporates a unique "Brazil
Switch" that provides convenient adjustment for the
weaker signals typically encountered near the magnetic
Simplified Operation - Designed for easy use by
non-skilled personnel, the G-856AX combines high accuracy
with convenient, push-button operation.
The G-856AX is compatible with PC's using RS-232
(serial) input. With the aid of a PC, the G-856AX permits
a wide range of processing styles. Averages may be run to
filter out near-surface magnetic anomalies, or regional
gradients may be removed to emphasize local information.
If data from a separate base station has been entered
into the computer, errors from temporal variations in the
magnetic field may be removed and interpolated data can
be generated to simplify contour mapping, or a complete
map can be produced. MagMap96, supplied with the G-856AX,
handles all basic processing, including parsing of GPS
info to the magnetic data, and export of data to Surfer
format for contouring and 3-D data display.
MagMap for Windows, a basic software
package, is supplied as an integral part of the G-856AX
system. It provides:
- Transfer of the raw data to the client PC;
- Standard corrections for position errors,
transients, and time varying errors (diurnal);
- Repositioning, linear interpolation and format
corrected data into X,Y,Z ASCII columnar values
for use with various contouring programs.
- Parsing of GPS data to magnetic data set
- DISPLAY: Six-digit display of
magnetic field to resolution of 0.1 gamma or time
to nearest second. Additional three-digit display
of station, day of year; line number; battery
voltage or signal strength.
- RESOLUTION: Typically 0.1 gamma
in average conditions. May degrade to lower
resolution in weak fields, noisy conditions or
- ACCURACY: One-half gamma,
limited by remnant magnetism in sensor and
crystal oscillator accuracy.
- CLOCK: Julian clock with
stability of 5 seconds per month at room
temperature and 5 seconds per day over the
temperature range of - 20 to + 50 degrees
- TUNING: Automatically tunes for
maximum signal strength after each reading.
Tuning may be manually adjusted to compensate for
high gradient shifts and for changes in length of
sensor cable. Tuning range covers 20 to 90
- GRADIENT TOLERANCE: Tolerates
gradients to 5000 gammas/meter. When high
gradients truncate count interval, maintains
partial reading to accuracy consistent with data.
Sounds audio alarm in high gradients or when
signal is weak.
- CYCLE TIME: Complete field
measurement in three seconds in normal operation.
Internal switch for faster cycle (1.5 seconds) at
reduced resolution or slower cycle for improved
signal. Auto-cycle time for base station
operation can be reduced to 2 seconds.
- MANUAL READ: Takes reading on
command. Will store data in memory on command at
- SELF-CYCLE: Internal switch will
cause the instrument to self-cycle, storing
automatically for time dependent measurements.
Available intervals are 4 to 999 seconds in
one-second increments selected by push buttons.
- MEMORY: In portable mode stores
over 1,400 readings with time of reading and
station number. In base station mode, stores over
2,500 readings with Julian date and time of
- OUTPUT: Standard RS-232
- INPUTS: Will accept an external
sample command and will synchronize reading with
- BEEPER: Sounds once when a key
is touched, three times after data have been
transferred through RS-232 port, and five times
in high gradients or when signal is weak.
- SPECIAL FUNCTIONS: An internal
switch allows lengthening or shortening
polarization time and count time to improve
performance in marginal areas, improve
resolution, shorten cycle time, increase battery
life, and to perform a 3-point average.
Instrument console: 18 x 27 x 9 cm; 2.7
Sensor: 9 x 13 cm; 1.8 kg.
Staff: 3 cm x 2.5 m; 1 kg.
- ENVIRONMENTAL: Meets
specifications from 0 to 40 degrees Celsius.
Operates satisfactorily from - 20 to 50 degrees
- POWER: Operates from 8 D-cell
flashlight batteries (or 12 volts external
power). May be operated at 18 volts external
power to improve resolution. Power failure or
replacement of batteries will not cause loss of
data stored in memory. Battery voltage measured
and displayed during polarization.
- STANDARD ACCESSORIES: Sensor,
Staff, Chest Harness, Two sets of Batteries,
Operating Manual, Applications Manual for
- OPTIONAL ACCESSORIES: Gradiometer
Configuration, RS-232 Interface Cable, Cold
Weather Battery Belt.
- Gradiometer - A gradiometer
configuration is available with the
addition of a second sensor and staff
attachments. Includes a secong sensor, staff
inserts & a remote switch. Unit sequentially
reads each sensor at 3 second intervals.
- Rechargeable Battery Kit -
Provides gel cell batteries with internal
mounting plate & battery charger.
being used in gradiometer mode
For more info or pricing, follow the Geometrics pointer at the
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Scientific Services , authorized representative for South /