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Low noise, high stability orthogonal fluxgate sensor for variometers |
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Janosek, M. (1), Butta, M.(1) |
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(1) Dept. of Measurement, Czech Tech. Univ. in Prague |
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We present a 1pT/sqrtHz @ 1 Hz orthogonal fluxgate sensor working on the first harmonics, with the white noise level of 0.3 pT, suitable for variometers.
The low noise is a combination of material selection, processing and encapsulation - we present how the ultra-low frequency noise (mHz range) largely depends on the sensor encapsulation. The sensor is manufactured of ~100um diameter amorphous core and is ~6cm long, allowing for replacing the common sensors occuring in state-of-the-art variometers. The high geometric directivity is also a benefit from the point of further variometer calibrations.
For sucesfully using the fluxgate sensor in a variometer, the key point in the electronic development was understaning and supressing the offseet drift of the sensor. We show schemes which sucessfully suppress the sensor temperature drift by alternating excitation.
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Instrumentation |
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poster |