Magnetometers
These links will take you to information about the following instruments (includes picture, description, specifications, sample packing lists, weights & dimensions, rental rates, and user manuals):
Geometrics G856 and G858
Schonstedt GA-52Cx
Subsurface Instruments Borehole Gradiometer
Home Page
Warning: the instrument specifications below are provided as a courtesy. Actual values may vary and need to be confirmed via the manufacturer.
Geometrics G856 and G858 Magnetometers
Description:
The Geometrics G856 and G858 magnetometers measure the Earth’s total magnetic field. The G856 magnetometers use the well-established proton precession technology, which provides accurate total field measurements. Its simple push button operation makes it ideal for teaching environments or as a base station to measure diurnal changes in the Earth’s magnetic field.
The G858 magnetometers are a fast sampling yet highly sensitive cesium vapor magnetometers with a graphical interface. Various modes allow the users to design surveys to their particular needs whether it is searching a site for metal by walking a site or by creating a grid where a user manually takes measurements with lines and stations. In addition, an operator can take continuous measurements in conjunction with a GPS. When requested, a second sensor can be provided to configure the magnetometers as gradiometers. This setup either widens the search zone or measures the vertical magnetic field gradient. The Geometrics G858 magnetometers are commonly used for UXO, archaeological, environmental, utility, and mineral exploration.
G856 Magnetometers Specifications:
Displays: 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, and line number.
Resolution: Typically 0.1 gamma in average conditions. Mayde grade to lower resolution in weak fields, noisy conditions or high gradients.
Absolute accuracy: One 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 Celsius.
Tuning: Push button tuning from keyboard with current value displayed on request.Tuning range 20 to 90T.
Gradient: Tolerates gradients to 1800 gammas/meter. When high Tolerance gradients truncate count interval, maintains partial reading to an accuracy consistent with data.
Cycle Time: Complete field measurement in three seconds in normal operation. Internal switch selection for faster cycle (1.5seconds) at reduced resolution or longer cycles for increased resolution.
Manual Read: Takes reading on command. Will store data in memory on command.
Memory: Stores more than 5700 readings in survey mode,keeping track of time,station number, line number day and magnetic field reading. In base station operation, computes for retrieval but does not store time of recording designated by sample interval, allowing storage of up to 12,000 readings.
Output: Plays data out in standard RS-232 format at selectable baud rates. Also outputs data in real time byte parallel, character serial BCD for use with digital recorders.
Inputs: Will accept an external sample command.
Special: An internal switch allows:
1) adjustment of Functions polarization time and count time to improve performance in marginal areas or to improve resolution or speed operation
2) three count averaging
3) choice of lighted displays in auto mode.
Physical:
1) Instrument console: 7×10½x3½ inches(18x27x9cm), 6LB(2.7kg), Sensor: 31/2×5 inches(9x13cm),4LB(1.8kg)
2) Staff: 1 inchx8 feet(3cmx2.5m), 2LB(1kg)
Environmental: Meets specifications from 1 to 40°C. Operates satisfactorily from -20 to 50°C.
Power: Depending on version, operates from internal rechargeable Gel-cells or 9D-cell flashlight batteries. May be operated from external power ranging from 12 to 18 volts external power. Power failure or replacement of batteries will not cause loss of data stored in memory.
G858 Magnetometers Specifications:
MAGNETOMETERS / ELECTRONICS
Operating Principle: Self-oscillating split-beam Cesium Vapor (non-radioactive CS-133).
Operating Range: 18,000 to 95,000 nT (ƴ)
Operating Zones: For highest signal-to-noise ratio, the sensor long axis should be oriented at 45°, ±30 °to the earth’s field angle, but operation will continue through 45°, ±35°. Sensor is automatic hemisphere switching.
Sensitivity: 90% of all readings will fall within the following P-P envelopes:
0.05 nT at 0.1 sec cycle rate (SX=0.160nT)
0.03 nT at 0.2 sec cycle rate (SX=0.113nT)
0.02 nT at 0.5 sec cycle rate (SX=0.072nT)
0.01 nT at 1.0 sec cycle rate (SX=0.051nT)
Information Bandwidth: < 0.004 nT (ƴ)/√Hz RMS
Heading Error: < ± 0.5 nT (ƴ) Temperature Drift: 0.05 nT per degree C Gradient Tolerance: > 500 nT (ƴ)/inch (>20,000 nT (ƴ)/meter
Cycle Rate: Variable from 0.1 sec to 1 hr in 0.1 sec steps or by external trigger.
Data Storage: Non-volatile RAM with capacity for 8 hrs of Magnetometer time, event marks, location, or 3 hrs of Gradiometer and GPS at maximum sample rates.
Audio Output:
1) Audio tone of earth’s field variation, pitch and volume adjustable. (Search)
2) Audio pulse each 1 second
(Pace metronome).
3) Alarm for loss of signal, noise in signal (QC) or low battery.
Data I/O: RS-232 standard bidirectional serial port, selectable continuous real time data transmission via RS-232 to PC. Memory dump transfer time less than 5 min at 115K baud transmission rate.
Visual Output: Micro-controller driven, 320 x 200 graphic liquid-crystal display, daylight visible with selectable outputs for:
1) Data display: Up to 5 stacked profiles, real time or review mode. Map of survey grid with zoom functions.
2) All system set-up functions, e.g., memory status, data transfer, sample time.
3) All Survey set-up functions, e.g., survey profile number and direction, station or GPS number,
4) Survey monitoring functions, e.g. total field, noise level, profile number x or xy coordinates.
Internal Clock: Resolution of 0.1 sec, drift: < 1 sec/day
Power:
1) 24 VDC rechargeable gel cell, 6 hrs Magnetometer or 3 hrs Gradiometer usage. Magnetic effect less than 1 nT ( ƴ) at 3 ft.
2) Internal backup battery for clock and non-volatile RAM.
External power input 22 to 34 VDC, 1 amp on turn-on, 600ma operating in magnetometer mode.
Software: Supplied as part of the basic system for installation in the Geometrics or client-supplied PC, and including functions for:
Operating Software:
1) Survey Modes:
a. Search
b. Simple survey, station or continuous
c. Map survey, station or continuous
d. Base station
2) Data acquisition/display:
a. Acquire and store data and survey functions.
b. Display profiles, total field to 0.1 nT resolution, gradient (differential) to 0.1 nT, survey/map parameters and diagnostics.
c. Map display showing location of all readings.
PC Support Software:
1) Data transfer and corrections:
a. Transfer of data from the field Magnetometer, Gradiometer, GPS, or Base station to the PC.
b. Diurnal correction using base station data.
c. Processing the corrected data into ASCII values of X-Y-Z for the magnetometer and/or X-Y-Z1-Z2-Z3 for the gradiometer.
2) Optional bundled “Surfer for Windows” by Golden. Provides data presentation/plotting into a contour map or 3D isomagnetic map with Text annotation and color blends.
MECHANICAL
Sensor: 2-3/8” dia., 6-3/4” long, 12 ounces
6 cm x 15 cm, 340 g
Console: 6” W, 3” H, 11” L, 3.5 lbs. (15 cm x 8 cm x 28 cm, 1.6 kg), attaches to harness. Magnetic effect less than 1 nT ( ƴ) at 3 ft
Battery: 3” H, 5” W, 8” L, 3.5 lbs (8 cm x 13 cm x 20 cm, 1.6 kg) attaches to harness.
Staff/Harness: Staff for Magnetometer or Gradiometer, 1.5 lb to 2.5 lb (0.9 kg to 1.1 kg)
Nylon chest harness with cables attached, 2 lb to 3 lb (1 kg to 1.3 kg)
ENVIRONMENTAL
Operating Temperature: -15C to +50°C (-13F to + 122F)
Storage Temperature: -35C to + 60°C (-30F to + 140F)
Water Tight: To 1 ft (0.3 m) depth for 10 seconds.
Shock: Drop 3 ft on a hard surface without damage
Typical packing list of items received when renting a Geometrics G856 Magnetometers:
1 x G-856 Console
1 x Sensor with Cable
3 x Sensor Aluminum Staff Sections
1 x Shoulder Harness
1 x Data Cable
1 x USB Adapter Cable
1 x USB with manuals and software
1 x Paper Operations Manual and Quick Reference Guide
*1 x Carrying Case (27”x12”x8”, 30lbs)
Typical packing list of items received when renting a Geometrics G858 Magnetometers:
1 x G-858 Console
1 x Sensor and Clamp (2 sensors by request)
3 x Sensor Aluminum Staff Sections ( 2 ft. long)
1 x Sensor Staff for Gradiometer Option if request (Aluminum Staff Sections 2 x 1 ft, 1 x Gradiometer Tee Adapter, 1 x Non-Ferrous Counter Balance Weight)
1 x Strap Clamp Assembly
1 x Shoulder Harness
1 x Staff Holster
1 x External I/O Cable
1 x USB to Serial Adapter Cable
2 x Battery Belt Pack Assembly
2 x Battery Charger
1 x USB Flash Drive with Software and Manuals
*1 x Carrying Case (31”x15”x12”, 65lbs)
*All dimensions are approximate and will vary depending on configuration and how each instrument is packed. Some shipping containers may be slightly larger/heavier than others containing the same instrument.
Suggested Items:
Hemisphere GPS
Items you may need to provide:
None
Software provided:
The Geometrics G856 and G858 magnetometers come with Geometrics Magmapper software on a USB flash drive. The software can also be downloaded from the Geometrics website.
Rental Rates for Magnetometers:
The Geometrics G856 rents for $30 per day or $720 per month with a $50 prep fee.
The Geometrics G858 with one sensor rents for $85 per day or $2,040 per month with an $85 prep fee.
The Geometrics G858 with two sensors rents for $110 per day or $2,640 per month with an $85 prep fee.
*** As a courtesy, we do not charge rent if the equipment is shipped on a Friday and in-transit with FedEx or UPS over Saturday, Sunday, and/or an approved holiday (only valid for rentals less than a month). In its sole and absolute discretion, Geophysical Equipment Rental LLC and/or K. D. Jones Instrument Corp reserve the right not to extend this courtesy.
Get an estimate to rent the Geometrics G856 or G858 magnetometers.
User Manual:
Schonstedt Magnetometers
Description:
The Schonstedt is a magnetic locator that detects ferrous metals. Essentially, the Schonstedt has two sensors that measure the magnetic field. One sensor is at the base of the instrument while the other is near the top of the instrument. The instrument compares the two magnetic fields and produces an audio tone frequency that increases as the signal strength increases. This basic unit is not used for collecting data to create contour plots.
Schonstedt Magnetometers Specifications:
Input Power: Supplied by two alkaline 9-V batteries
Battery Life: 40 hours (Intermittent usage)
Output: Approximately 40 Hz idle tone in speaker. Tone frequency increases (or decreases) with gradient-field intensity.
Weight: Approximately 2.5 lbs. (1.13 kg)
Operating Temperature: -13° F to 140° F (-25° C to 60° C)
Overall Length: 42-5/16 in (107.4cm)
Waterproof Length: 34-1/2 in. (87.6 cm)
Nominal Sensor Spacing: 20 in. (50.8 cm)
Construction: Rugged, modular all solid state
Typical packing list of items received when renting Schonstedt magnetometers:
1 x Schonstedt
1 x User manual
*1 x Carry Case (46”x6”x5”, 6lbs)
*All dimensions are approximate and will vary depending on configuration and how each instrument is packed. Some shipping containers may be slightly larger/heavier than others containing the same instrument.
Suggested Items:
None
Items you may need to provide:
Extra 9v batteries (two)
Software provided:
None
Rental Rates for Magnetometers:
The Schonstedt rents for $15 per day or $360 per month with a $30 prep fee.
*** As a courtesy, we do not charge rent if the equipment is shipped on a Friday and in-transit with FedEx or UPS over Saturday, Sunday, and/or an approved holiday (only valid for rentals less than a month). In its sole and absolute discretion, Geophysical Equipment Rental LLC and/or K. D. Jones Instrument Corp reserve the right not to extend this courtesy.
Get an estimate to rent the Schonstedt.
User Manual:
Subsurface Instruments Borehole Gradiometer
Description:
The borehole gradiometer works much like the other magnetometers, measuring the magnetic field with two different element locations within the sensor housing. This difference is measure and reported to the user via the LCD display and an audio frequency. Unlike other magnetometers, this sensor possesses the ability to go down a borehole that measures under 2 inches in diameter.
Borehole Gradiometer Specifications:
Controls:
ON, OFF
Volume UP and DOWN
Range setting (Gain or Sensitivity) UP and DOWN
Zero, Plus and Minus
Auto Zero – Automatic self-adjusting
Battery Check
Outputs:
Audio Frequency pitch (Speaker & jack for headset)
Visual LCD Display
Bar graph – Range GAIN setting – Milligauss
RS-232 PC connection (cable included)
Control all keypad functions
Data log range, keypad & signal settings
Works with hyper terminal or equivalent
Power Options:
Internal battery: 12 volt, 7.2Ah sealed lead acid
Battery Life: 72 Hours continuous use
Charges to full overnight
External Power 12 to 15 volt, cable included
Internal battery charging circuit is enabled when external power or the wall transformer is connected .
Operating temperature range:
-20F to 150F (-29C to 66C)
Dimensions:
Electronics: 18.5 X 14.5 X 7.5
Sensor: 1.625 X 17.5
Typical packing list of items received when renting a Borehole Gradiometer:
1 x BHG Console
1 x BHG Sensor
1 x 100ft Cable
1 x Sensor Deployment/Recovery Rope 100ft
1 x Console Battery Charger
1 x External Charger
1 x Download Cable
1 x USB Adaptor
1 x BHG Manual
*1 x Shipping Case (28”x21”x16”, 52lbs)
*All dimensions are approximate and will vary depending on configuration and how each instrument is packed. Some shipping containers may be slightly larger/heavier than others containing the same instrument.
Suggested Items:
None
Items you may need to provide:
None
Software provided:
None
Rental Rates for Magnetometers:
The Subsurface Instruments Borehole Gradiometer rents for $40 per day or $960 per month with a $60 prep fee.
*** As a courtesy, we do not charge rent if the equipment is shipped on a Friday and in-transit with FedEx or UPS over Saturday, Sunday, and/or an approved holiday (only valid for rentals less than a month). In its sole and absolute discretion, Geophysical Equipment Rental LLC and/or K. D. Jones Instrument Corp reserve the right not to extend this courtesy.
Get an estimate to rent the Subsurface Instruments Borehole Gradiometer.