Magnetometers for a Geomagnetic and Seismic Combined Survey

The Laboratory of Magnetic Sensors Development (LDMS/ON) from the Observa- torio Nacional develops and builds high sensitivity fluxgate sensors and magnetom- eters using nanocrystalline and amorphous alloys. The Seismological Team of the Observatorio Nacional leads seismic studies using data from the IRIS Consortium. Six stations using broadband seismometers and high resolution fluxgate magnetom- eters to work combined are being installed in the Rio de Janeiro State. The devel- oped magnetometers have high sensitive ring-core sensors made using nanocrystalline (FeSiCuNbB) alloy. The system records magnetic data in a range (0.001-100) Hz with resolution 0.1 nT and noise: 800 pT (rms).