High-end stable variometer for geomagnetic observatories and variometer stations.
This well known Danish magnetometer is a
3-axis variometer and has a proven track-record at many observatories worldwide.
It is easy to set up and operate and has demonstrated
baseline stability over decades. Previously offered under the name FGM-FGE, the
FGE is assembled and calibrated by DTU Space.
More than 250 FGE magnetometers are
installed at geomagnetic observatories and variometer stations worldwide. DTU Space itself is operating more than 20 FGE magnetometers, most of them in Greenland.
The main idea behind the FGE was to construct
a reliable and very stable instrument that is easy to set up and operate. In
order to avoid drift due to tilt of the instrument pier, which is often the
main cause of baseline drift, the most popular version of the FGE has the
sensors suspended by two crossed bronze bands to compensate for pier tilt.
The FGE is suitable for digital recording
of the magnetic field at observatories or variometer stations. The FGE has
analog outputs enabling the user to adapt the instrument to their own data
logging systems. An optional built-in AD-converter is also available.
3 linear core fluxgate sensors mounted on a marble cube for good mechanical stability.
Bias and feedback coils on quartz tube for high temperature stability.
Highly stable digitally controlled compensation of main field. Very good long-term stability.
Magnetically very clean electronics which may be placed rather close to the sensor head. Temperature sensors in the FGE-sensor head and the electronics.
Battery operation. 10-18 VDC, 3 W
Build-in 16 bit AD-converter (Adam module)
Extension sensor cable between FGE-sensor and electronics up to 100 meter
Low temperature (-30 °C) versions with silicone cables and low viscosity damping oil
Spare magnetometer electronics , works with all versions of the FGE magnetometer
||User specified (100-1000 nT/Volt)
||around 40 pT
|Compensation field range:
||±64 000 nT
|Compensation field steps:
|Misalignment of sensor axis:
||< 2 mrad (optional <1 mrad)
|Long time drift:
||< 3 nT/year
|Temp. coeff. of sensor:
||< 0.3 nT/°C
|Temp. coeff. of electronics:
||< 0.1 nT/°C
||DC to 1 Hz (optional 10 Hz)
Spec. of optional suspension
|Range of tilt compensation:
|Factor of tilt compensation:
|| > 200
|Size of standard (non-suspended) system:
|300 x ø270 mm; 9.5 kg
|Size of suspended system:
|550 x ø270 mm; 20 kg
|Size of electronics:
|160 x 90 x 360 mm; 3.0 kg
|230 VAC, 110 VAC or 12 VDC, 3W
0 to 60°C
down to -30°C for low temperature version