G-882

G-882

Category： Cesium optical pump magnetometer

Model： G-882

Brand： Geometrics

Quantity： 1

Instrument： Non-shipboard Instrument

Equipment Condition： Normal

Maintenance Manager

Chang Hsuan-Cheng
Technician III
(02)3366-7282
samsonchang@ntu.edu.tw

Function Description

G-882 Subsea Magnetometer is produced by Geometrics. The towing fish measures 137 cm in length and 7 cm in width, with a weight of approximately 18 kg in air. It is an Overhauser-type magnetometer using Cesium (Cs) as the alkali metal in the sensor. With excellent sensitivity (0.002 nT) and sampling rate (up to 20 Hz), it allows for measurements at higher ship speeds, saving significant survey time. The G-882 can withstand pressures up to 2700 meters in depth. Its control and data collection software is MagLog™.

Typical Applications:

  • UXO (Unexploded Ordnance) detection and clearance

  • Subsea pipeline and cable location

  • Shipwreck and archaeological site investigation

  • Geological and mineral exploration

Borrowing Rules

Please contact the equipment technician.

Equipment Description

Main Specifications:

  • Operating Principle: Self-oscillating split-beam Cesium vapor sensor (non-radioactive)

  • Measurement Range: 20,000 to 100,000 nT

  • Sensitivity: < 0.004 nT/√Hz RMS

  • Absolute Accuracy: < 2 nT

  • Sampling Rate: Up to 20 Hz

  • Output Interface: RS-232, Baud Rate 1,200 to 19,200

  • Power Requirements: 24 to 32 VDC, 0.75 A during startup, 0.5 A during operation

  • Operating Temperature Range: -35°C to +50°C

  • Storage Temperature Range: -45°C to +70°C

  • Maximum Operating Depth: 2,730 meters (4,000 psi)

Mechanical and Structural:

  • Sensor Dimensions: Diameter 7 cm, Length 137 cm (including tail fin)

  • Weight: 18 kg (including main weight); additional weights of 6.4 kg each, can be added up to over 100 kg for deep tow applications.

  • Tow Cable: Standard length of 200 ft (61 m), extendable to 800 m; break strength of 1,630 kg.

Additional Features and Accessories:

  • Built-in CM-221 Counter: Provides multi-sensor synchronization and data integration functionality.

  • Optional Depth Sensor and Altimeter: Real-time monitoring of towfish depth and height above the seafloor.

  • Supports Multiple Towing Configurations: Can be quickly converted to either nose tow or center of gravity tow modes.

  • Integration with MagLog™ Software: Allows data logging, display, and GPS position synchronization.

Maintenance & Attendance Records

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