The G-858 MagMapper is a high-performance cesium magnetometer comprised of a belt-mounted console connected to a cesium sensor on a handheld counterbalanced staff.
Features & Benefits
Single or Dual Sensor Modes – Easily go from a single sensor survey to either a vertical or horizontal gradiometer survey.
Low Noise/High Sensitivity – Pick up the smallest changes in magnetic field.
Fast Sampling – Save money and time on large-scale surveys; detect the smallest objects.
Low AC Field Interference – Survey next to power lines when necessary.
Easy-to-use Interface – Useable by inexperienced personnel.
Rugged and Reliable – Weatherproof. Survives three-foot drop onto hard surface.
Ultra-stable – No need to calibrate sensors.
Long Battery Life – Each battery pack allows for 6 hours of surveying with single sensor and 4 hours with gradiometer.
Optional Ergonomic Backpack & GPS – Upgrade to a complete survey system at any time. Provides more comfort during and after survey.
Optional Non-Magnetic Cart – Attach two or more sensors to our MagCart for large surveys looking for near- surface features.
Operating Principle: Self-oscillating split-beam Cesium Vapour (non-radio- active Cs-133) with automatic hemisphere switching.
Operating Range: 20,000 nT to 100,000 nT.
Operating Zones: For highest signal-to-noise ratio, the sensor long axis should be oriented at 45°, ± 30 to the earth’s field but operation will continue through 45°, ± 35°. Sensor is automatic hemisphere switching.
Noise: < 0.008 nT/√Hzrms (SX (export) version: 0.02 nT/√Hzrms).
Heading Error: < 1.5 nT including backpack and GPS.
Gradient Tolerance: > 500 nT/in (>20,000 nT/m).
Temperature Drift: < 0.05 nT/°C.
Max Sample Rate: 10 Hz.
Data Storage: Non-volatile RAM with capacity for 8 to 12 hrs of magnetometer, time, event marks, field notes and XYZ or GPS locations.
1. Audio tone of field variation; pitch and volume adjustable. (Search mode).
2. Audio pulse each 1 second (pace metronome).
3. Alarm for loss of signal, low battery or quality control setting exceeded.
Data Output: Three-wire RS-232 standard serial port, optional continuous real-time transmittal of data via RS-232 to PC. Total memory output transfer time less than 5 min at 115,200 baud.
Visual Output: 320 x 200 graphic liquid-crystal display, daylight-visible with selectable outputs for:
1. Display of up to 5 stacked profiles, real time or review mode. Survey grid showing boundaries and position.
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 number or GPS data transfer protocol, line number.
4. Survey monitoring functions, e.g. total field, noise level, profile number or x-y coordinates.
Internal Clock: Resolution of 0.1 sec, drift: < 1 sec/day.
Power: 24 VDC rechargeable gel cell, 5hrs for Mag w/GPS.Magnetic effect less than 1.5 nT at 4 ft. Internal backup battery for clock and non-volatile RAM.
1. Survey Modes: Search survey – Simple survey – Mapped 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 resolution, survey /map parameters and diagnostics.
Post-acquisition Software: MagMap software for installation on customer’s computer.
1. Data transfer and corrections:
a. Transfer of data from field Magnetometer, GPS, or Base station to PC.
b. Diurnal correction using base station data.
c. Processing the corrected data into ASCII values of X-Y-Z.
2. Data processing functions include spike editing, spline filtering, repositioning of X, Y, Z or GPS Lat/Long, conversion to UTM coordinates, profile and contour map plotting.
Sensor: DIA: 6 cm; L: 15 cm; Weight: 340 grams.
Console: L: 28cm; W: 15cm; H: 8cm; Weight: 1.6kg. Magnetic effect less than 1 nT at 4 ft.
OperatingTemperature: -25°C to +50°C.
StorageTemperature: -35°C to +60°C.
Water Tight: Weatherproof in driving rain.
Shock: Survives a 3ft drop onto a hard surface.
Warranty: 1 year on G-858 and sensor, 1 year on accessories.
G-858AP: Includes ergonomic backpack and Tallysman GPS.
Tallysman TW5341TM Specs:
- Code and carrier phase tacking with 1Hz Position, velocity, time output.
- SBAS capable and designed for harsh environments.
- RS-232 compatible interface.
Size and Weight: DIA: 66.5mm; H: 21mm; Weight: 60 g .
Input Voltage: +9 to +16 VDC.
Power Consumption: 1.2W (typical).
Com Ports: 1RS-232 (optional 2 RS-232) at up to 19,200 baud.
Operating Temperature: -40°C to +85°C.
Position Accuracy: Single point L1 <2 m CEP; WAAS L1 <1 m CEP.
Data Rates: Measurements 1 Hz; Position 1 Hz.
Time to First Fix: Cold start 39 sec; warm start 34 sec; hot start 2.5 sec.
Signal Reacquisition: <1 sec typical.