home     corporate website     site map     contact  
 
 
Home
 
  about Fugro Instruments     services     careers     technical papers    
 
 
Fugro Instruments

G-858 MagMapper Specifications @ Fugro Instruments

G-858 MagMapper System
Technical specifications
OPERATING PRINCIPLE
- Self-oscillating split-beam Cesium Vapour (non-radioactive Cs133) with automatic hemisphere switching

OPERATING RANGE
- 17,000 nT to 100,000 nT

OPERATING ZONE
- For highest signal-to-noise ratio, the sensor long-axis should be oriented at 45°, ± 30° to the earths field angle, but operation will continue 45°, ± 35°. Sensor is automatic hemisphere switching.


SENSITIVITY
- 90% of all readings will fall within the following peak-to-peak envelopes : - 0.05 nT at 0.1 sec cycle rate
- 0.03 nT at 0.2 sec cycle rate
- 0.02 nT at 0.5 sec cycle rate
- 0.01 nT at 1.0 sec cycle rate

INFORMATION BANDWIDTH
- < 0.004 nT / sqrt(HzRMS)

HEADING ERROR
- < ± 1 nT

GRADIENT TOLERANCE
- > 500 nT / inch >20,000 nT / metre

TEMPERATURE DRIFT
- 0.05 nT per °C

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 of 8 hrs of magnetometer time, event marks, field notes, location, or 3 hrs of gradiometer or 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, low battery, or exceeding qualitycontrol setting

DATA OUTPUT
- Three wire RS232 standard serial port, optional continuous real time transmittal of data via RS232 to PC. Total memory output transfer time less than 5 min. at 115,200 kBaud.

VISUAL OUTPUT
- 320 x 200 graphic LCD, daylight visible with selectable outputs for :
- 1. Data Display : Up to 5 stacked profiles, real time or review mode. Survey grid showing boundaries and position.
- 2. All system setup functions. eg. memory status, data transfer, sample time
- 3. All survey setup functions. eg. survey profile number and direction, station or GPS number, test line number
- 4. Survey monitoring functions. eg. total field, noise level, profile number x or xy coodinates.
- 5. System diagnostics. eg. lamp brightness, signal level, battery state.

INTERNAL CLOCK
- Resolution of 0.1 sec, drift: < 1 sec per day

BATTERY LIFE
- 1. 12 VDC rechargeable gel cell, 6 hrs magnetometer or 3 hrs gradiometer usage. Magnetic effect less than 1 nT at 1.5m.
- 2. Internal battery backup for clock and non-volatile RAM

SOFTWARE
- Supplied as part of the basic system and including functions for :
Operating Software :
1. Survey Modes : Search survey, simple survey, map survey, station or continuous, base station.
2. Data Acquisition / Display : Acquire and store data and survey functions, display profiles, total field to 0.1 nT, survey/map parameters and diagnostics.
PC Support Software for installation on customer or Geometrics supplied data processing computer:
1. Data Transfer and corrections : Transfer of data (from the field magnetometer, gradiometer, differential GPS, or base station PC), diurnal correction using base station data, processing the corrected data into ASCII values of XYZ for the magnetometer and/or XY Z1 Z2 Z3 for the gradiometer.
2. Optional "Surfer for Windows" by Golden for presentation/plotting of contour maps and 3D isomagnetic maps.

DIMENSIONS & WEIGHT
- Sensor : 6cm x 15cm / 340 grams
- Staff/Harness for magnetometer or gradiometer : 0.9kg to 1.1kg
- Nylon chest harness with cables attached : 1 to 1.3 kg
- Battery : 8cm x 13cm x 20cm / 1.6kg
- Console : 15cm x 8cm x 28cm / 1.6 kg

OPERATING TEMPERATURE
- 25°C to +50°C

STORAGE TEMPERATURE
- 35°C to +60°C

WATER TIGHT
- To 0.9 m

SHOCK
- Drop from 1m onto a hard surface without damaging

OPTIONS
- 1. Gradiometer, horizontal and/or vertical configuration.
- 2. GPS navigation (real time differential with radio link to GPS base station or FM transmitted RTCM codes.
- 3. MagAID Anomaly Identification Software, for use in estimating position, size and depth of source bodies and buried objects.
 G-858 MagMapper System

The G-858 MagMapper System is a fast-sampling Cesium vapour magnetometer used for professional mapping in minerals, petroleum and environmental/search applications. It comprises a belt-mounted display and acquisition console connected to a cesium sensor mounted on a hand-held counterbalanced staff. The console contains electronics to acquire magnetic field data with position information, and then display the data on a LCD screen for review and edit.

Features & Advantages:

Increased Sensitivity - 0.05 nT to 0.01 nT

Increased Measurement Rates - 10 Hz to 1 Hz

LCD Display of up to five stacked profiles (positions linearly interpolated)

Interactive Map Display - Graphic display of the survey grid with way-point markers and current position, and many other unique functions to provide precise high resolution maps

Rapid Acquisition - Magnetic data may be acquired at a fast walking pace and can include GPS data if available. Internal memory provides storage of up to 250,000 data points, each with position and time stamp. This provides over eight hours of operation at a maximum cycle rates of ten times per second

Applications:

  • Petroleum and mineral exploration,
  • Environmental surveys,
  • Archeological investigations,
  • Unexploded ordnance
  • Detection and mapping of pipelines, cables and other utilities.


The system is especially powerful for use in detailed environmental investigations where the very high sensitivity and sampling rates not only detect but facilitates accurate mapping of very subtle features frequently missed in the past.

TYPICAL DATA OUTPUT

 
IC    |    Disclaimer    |   Fugro © 2006