Noise and offset of a magnetometer

Offsets of the Sensors

With the calibration coil system the Earth's magnetic field can be compensated down to couple of tens of nT in all directions. The magnetometer sensor is installed in this near zero fields on a non-magnetic Askania theodolite. Thereafter the magnetic field is measured with the sensor in two opposite directions. By repeating this measurement few times, an accuracy of ±1 nT can be achieved.
 

Noise of the Sensors

The laboratory has a three-layer magnetic screen, which is used for the noise measurements. The screening effect of the chamber in perpendicular direction is 130,000 and the inner diameter of the chamber is 12 cm.