Digital compact proton magnetometer was created for measure the geomagnetic fields, including the fields of high heterogeneity. We described design of the instrument and its principles of operation. This device is using implemented digital filtering techniques and Prony method to determine the frequency of the desired signal. The experiments were made in the fields of high heterogeneity and demonstrated the possibility of precise measurements in the fields with a gradient of up to 8 mT / m. The device can be used as a metal detector, as well as for magnetic prospecting, geological studies, etc.
Keywords: nuclear magnetic resonance, free precession, proton magnetometer, geomagnetic field, digital filtering, Prony method
Information about authors of issue №1 (2013)
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The problem of interaction of mutually perpendicular magnetic fields in superconductors is considered. Possibility of use of a nonlinear susceptibility of superconductors for measurement of a magnetic field is shown, the assessment of sensitivity of the cryogenic probe magnetometer is carried out.
Keywords: superconductor, magnetometer, SQUID, cryotron, the crossed magnetic fields, non-linear magnetic, cryogenic probe
Analog-to-digital converter, with modulation, amplification and demodulation of the input signal is carried out. To compensate the additional error of voltage conversion, concerned with temperature instability, used dynamic cancellation technique, based on the correlation between offset voltage and modulator temperature fluctuation. ADC with response time 0.85 s performs the threshold of sensitivity 1 nV; 8,5 s - 0,31 nV, 85 s - 0.13 nV, 850 s - 0.1 nV, respectively, in the full-scale range 400 mV. Estimation of offset voltage temperature drift is 40 pV / ºC, time drift - 100 pV / h.
Keywords: analog-to-digital converter, ADC, error cancellation.
Information about authors of issue №4 p.1 (2012)
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`Described is the methodology of studying of topology of tensor quantity of magnetic field of leakage of natural defects in the natural geomagnetic field magnetization, which is the base for realization of digital Hall defect scope. Using this set it was managed to register the defects with the peculiar size of 15 microns in steel wire, which is used for reeling of butter spring of trucks.
Keywords: non-destructive testing, Hall-effect sensor, magnetic tomography.
Information about authors of issue №2 (2012)
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Information about authors of issue №4 (2011)
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