Instrument Details :- Make : Danish Technical University.(DTU), Model: FGE
Specification:- Analog output: ±10V, Dynamic range: (100-1000 nT/Volt),
Noise: around 40 pT, Compensation field range: ±64 000 nT,
Long time drift: < 3 nT/year, Temp. coeff. of sensor: < 0.3 nT/°C,
Temp. coeff. of electronics: < 0.1 nT/°C, Power requirements: 12 VDC, 3W
Operating temperature: 0 to 60°C
This instrument is the main instrument in our magnetic observatories.
We have 12 magnetic observatories having 2 magnetometers at each place, one main and other as backup.
DFMs are installed in all magnetic observatories of IIG.
A fluxgate magnetometer consists of a small, magnetically susceptible core wrapped by two coils of wire. An alternating electric current is passed through one coil, driving the core through an alternating cycle of magnetic saturation ; i.e., magnetized, non-magnetized, inversely magnetized, and so forth. This constantly changing field induces an electric current in the second coil, and this output current is measured by a detector. In a magnetically neutral background, the input and output currents match. However, when the core is exposed to a background field, it is more easily saturated in alignment with that field and less easily saturated in opposition to it. Hence the alternating magnetic field, and the induced output current, are out of step with the input current. The extent to which this is the case depends on the strength of the background magnetic field. Often, the current in the output coil is integrated, yielding an output analog voltage, proportional to the magnetic field.
Applications :As variometer to measure changes in earth’s magnetic field in three orthogonal directions.
Locations: All sites including Maitri and Bharati
Any request for data will be guided by the Institute’s Data Policy as described in the Institute web page