Scientific Sensors

 

SEAM uses flux-gate magnetometer for DC magnetic field measurement. Further decrease the noise level of the flux-gate magnetometer will be achieved by a modification of the flux-gate magnetometer sensor construction and searching for new methods of sensor magnetic core preparation, e.g. by improving the annealing process using the setups and methodology available at LEMI. Use of new electronic components in the noise-critical parts of the signal chain is also investigated in order to improve the performance of the instrument.

The following parameters are expected to be achievable for the flux-gate magnetometer:

Measuring range of total magnetic field ± 64 000 nT
Frequency range DC...10 Hz
Noise level at 1 Hz < 20 pT/√Hz
Sensor dimensions 20x20x21 mm3
Sensor mass 25 g

A novel miniature AC magnetic sensor is developed along the most promising directions based on the experience from preliminary studies. The first is to investigate the efficiency of using field concentrators for super-short cores. The second is to develop a new design of super-low noise amplifier. Finally, special attention is paid to the optimisation of the complete "sensor-amplifier" system. The search-coil magnetometer analog stages will be conditioned together with the analog-to-digital converter, the work to be done jointly by LEMI and BLE.

The following parameters are expected to be achievable for induction magnetometer:

Frequency range 40 Hz ... 20 kHz, flat response
Noise level at 1 kHz 0.3 pT/√Hz
Transformation factor 20 mV/nT
Sensor dimensions 38x38x38 mm3
Sensor mass 76 g