Definition - What does Magnetometer mean?
A magnetometer is a sensor used in directional drilling that detects and measures the strength of the Earth’s magnetic field along a fixed axis. This sensor is an integral component of the drill’s directional system embedded in a sensor module behind the drill bit. In combination with the accelerometers that comprise the sensor module, the magnetometer provides directional measurements (azimuth) to assist in the accurate reading of the drill and borehole inclination/orientation.
Trenchlesspedia explains Magnetometer
In directional drilling, the inclination and orientation of the drill bit are the most essential parameters to ensure that the borehole is drilled accurately and to specification. In order to achieve this, drill bits are outfitted with a directional system which comprises of magnetometers and accelerometers.
This system allows for measurement/logging while drilling and provides the operator with real-time information that can be used to adjust the drill path accordingly. The three mounted accelerometers measure inclination while the three magnetometers measure direction. When used in combination, these sensors ensure boreholes are drilled safely, accurately and efficiently by providing directional data and information on surrounding geological features.