Table T12. Specifications of the Goettingen borehole magnetometer.
Borehole magnetometer Three-component fluxgate
Power supply 50 V/0.25 A (12 W)
Random walk of fluxgate sensors <0.1 nT
Range ±50 µT
Resolution 6.1 nT
Data transmission Digital two-wire Manchester encoded
Sample rate Eight readings from 8 channels/s
Data acquisition system Personal computer (DOS)
Tool weight 68 kg
Tool length 3.5 m
Tool diameter 86 mm (3.375 in)
Housing Low magnetic monel
Nonmagnetic bronze centralizers (2) 16.3 kg each
Maximum operation temperature 0°-700°C (limited by FOG)
Maximum operation pressure 70 MPa
Recommended logging speed 360 m/hr
Maximum logging speed 3600 m/hr (limited by hole diameter)
Tool navigation system Three FOG µFORS-36 m (LITEF)

Note: FOG = fiber-optic gyro, µFORS = miniature fiber-optic rate sensor.