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1 MAGNETOMETRY Theoretical and experimental research Baltag Octavian Ioan Ligns of force of the geomagnetic field (Glatzmaier et Roberts, 1995).

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Presentation on theme: "1 MAGNETOMETRY Theoretical and experimental research Baltag Octavian Ioan Ligns of force of the geomagnetic field (Glatzmaier et Roberts, 1995)."— Presentation transcript:

1 1 MAGNETOMETRY Theoretical and experimental research Baltag Octavian Ioan Ligns of force of the geomagnetic field (Glatzmaier et Roberts, 1995).

2 B.Sc. in Physics - specialized in Electroradiophysics "Alexandru Ioan Cuza" University of Iasi 1982 Ph.D. with a thesis entitled "Contributions to development of low magnetic fields magnetometers" Central Institute of Physics - Bucuresti

3 3 THEORETICAL AND APPLICATIVE RESARCH IN MAGNETOMETRY DIRECTIONS MAGNETOMETRY  Space applications  Marine applications and naval degaussing  Terrestrial – special applications  Laboratory – research & industry MAGNETIC DETECTION  Magnetic naval and terrestrial mines  Industrial applications - buried metallic bodies METROLOGY, TRANSDUCERS & SPECIAL DEVICES PROTECTION OF INTELECTUAL & INDUSTRIAL PROPERTY  Patents  Trademarks ELECTROMAGNETIC COMPATIBILITY  Special applications  Research & industry

4 4 HIGH RESOLUTION MAGNETOMETRY  Biomedical applications MICROWAVE RADIOMETRY  Microwave Thermografy – early detection of the breast cancer RESEARCH DOMAIN

5 5 MAGNETOMETRY  Theoretical & experimental research on the fluxgate transducers for low magnetic field U 2f h I ex h h H ex h + H ex h - H ex h H ex U 2f I ex h h U 2f Iex h ferrofluid

6 6 Fluxgate diagram B H B tt +B s -B s d  /dt tt h>0 h=0 tt H=H 0 sin  t h>0 Core I Core II tt U 2f H 

7 7 RESULTS AND APPLICATIONS  Research on the fluxgate transducers & magnetometer electronics – applications for Intercosmos satellites Technical data: range: +/ nT frequency of pulse excitation: 2 kHz, second harmonic: 4 kHz noise: < 1 nT nonlinearity : < 1% applications: triaxial magnetometer for Intercosmos satellites

8 8 FLUXGATE WITH MULTIPLE PATH OF FLUX patent RO, nr , Int. Cl. G01R33/00  Fluxgate sensor with multiple path of flux, O. Baltag, D. Costandache„ “Studies in applied electromagnetics and mechanics”, vol.13, pp , 1998, Editor: V. Kose, J. Sievert, IOS Press- Amsterdam, ISSN: Specifications: Measuring range: +/ nT noise: < 1 nT excitation: pulse liniarity: < 1% Core: permalloy processed by photogravure, trated in hidrogen, coil support: noril and cuartz powder

9 9 FLUXGATE WITH MULTIPLE PATH OF FLUX patent RO, nr , Int. Cl. G01R33/00

10 10 NONLINEAR RESONANCE PHENOMENA IN FLUXGATE Fluxgate transfer characteristic in nonlinear resonance regime Specific phenomena: In certain operation conditions the fluxgate transducer no longer works as a magnetic field sensor and it is generating an almost quasisinusoidal signal with a frequency equal to the odd or even harmonics of the excitation signal The second harmonic phase can only be changed (with 180°) by applying a continuous or alternative magnetic field exceeding the threshold value characteristic to the regime.

11 11 Fluxgate – nonlinear resonance Transfer characteristic U 2ω = f (h) of the fluxgate in second harmonic resonance regime Hysteresis response to applied field of the fluxgate on second harmonic: - U Q second harmonic quadrature component - U S second harmonic, sinphasic component - U A second harmonic amplitude - H external magnetic field U 2f second harmonic amplitude H external magnetic field U ex excitation voltage f excitation frequency

12 12 Nonlinear resonance - Applications  Double pumping magnetometer and measuring method, patent Ro, No , Int. Cl. G01R33/02  Functional instability of ferromagnetic sensor in nonlinear resonance regime, digest, INTERMAG 96, Seattle, 1996  Pecularities of the fluxgate responses in the parametric resonance regime, O. Baltag, D. Costandache, Sensors Letters, Vol. 7, No.3, pp. 276–277 (2009) Excitation frequency f=2000Hz: first pumping frequency External magnetic field frequency F=200Hz: second pumping frequency

13 13 DOUBLE PUMPING MAGNETOMETER Patent RO, no , Int. Cl. G01R33/02 Fluxgate responses U 2f (second harmonic 2f) at second pumping field F=200Hz, and measuring field Ho Second harmonic U 2f of the fluxgate modulated in amplitude by second pumping field with frequency F=200Hz Functional characteristics: first pumping frequency (fluxgate excitation): f=2 kHz second pumping frequency: F=200 Hz noise: < 0,1 nT measuring range: +/ nT

14 14 FERROFLUID FLUXGATE TRANSDUCER  Behaviour of some nonlinear devices with ferrofluid, O. Baltag, D. Costandache, C. Cotae, JMMM, vol. 157, pp. 591,1996  Magnetometer with ferrofluid sensor, Baltag O., D.Costandache, IEEE Instrumentation & Measurement Technology Conference IMTC 96, Brussels, 1996, pp , ISBN: , IEEE Xplore, INSPEC Number:  Sensor with ferrofluid for magnetic measurements, O. Baltag, D. Costandache, IEEE Trans. on Instrumentation and Measurement, vol. 46, nr.2, pp , 1997  Nonlinear behaviour of the ferrofluid in orthogonal magnetic fields, O. Baltag, D. Costandache, JMMM, 201, pp , 1999  The study of a magnetic fluid based sensor, C. Cotae, O. Baltag, R.Olaru, D.Calarasu, D.Costandache, JMMM, 201, pp , 1999  Sensor with ferrofluid for magnetic measurements, O. Baltag, D. Costandache, Conference on Precision Electromagnetic Measurements, Braunschweigh, June 1996, CPEM-96, pp.61-62, ISBN:

15 15 FERRITE FLUXGATE  Gaussmeter, O.Baltag, D. Costandache, IEEE Proceedings of the International Symposium on Signal, Circuits & Systems, Iasi 1995, pp. 473  Magnetic field measurement with soft ferrite cored sensors, Baltag O., D. Costandache, 7-th, International Conference on Ferrites, Bordeaux,1996  Toroidal Fluxgate Sensor Compared in Dynamic Preisach Framework, Salceanu A., Baltag O., Costandache D., The 7-th European Magnetic Materials and Applications Conference, EMMA ‚98, Zaragoza, Spain, pp. 248

16 16 AMORPHOUS AND NANOCHRISTALINE FLUXGATE  Preisach approach for modelling an amorphous toroidal fluxgate sensor, A. Salceanu, O. Baltag, D.Costandache, Sensor and Actuators, A, vol. 81, pp , 1999, ISSN:  Study of a magnetic field sensor with nanocrystalline materials, Salceanu A., Baltag O., et all, Bul.Inst.Politehnic Iaşi, Tom XLV (IL), Fasc.5A, pp , 1999, ISSN  Fluxgate sensor with nanocrystaline ferromagnetic core, Baltag O., M.Craus, D. Costandache, "43 Internationales Wissenschaftliches Kolloquium", Ilmenau, sept  Study of a ferrite sensor for medium magnetic field intensity measurement, O. Baltag, D. Costandache, A. Salceanu, Studies in applied electromagnetics and mechanics, in „Studies in Applied Electromagnetics and Mechanics”, vol.18, Editori: P.di Barba, A. Savini, pp , 2000, IOS Press-Amsterdam, ISSN:

17 17 ELECTRONIC CIRCUITS FOR FLUXGATE MAGNETOMETER Electronic devices for fluxgate excitation and generating of reference signal, Patent RO., No (1982), Int. Cl. G01G33/02

18 18 ELECTRONIC CIRCUITS FOR FLUXGATE MAGNETOMETER  Negative feedback network Fluxgate Reference 2f Frequency divider 1/2 Synchro- nous Detector Phase shift Selective amplifier Excitation generator Generator 2f f D.C. Amplifier Negative feedback circuit Excitation Generator   S UeUe h hrhr irir UrUr Feedback coil K u, K i, r r U r =  U e UsUs Reference 2f

19 19 ELECTRONIC CIRCUITS FOR FLUXGATE MAGNETOMETER  Integrated hybrids circuits for magnetometry - ceramics support - resistors – laser trimming - active components: integrated circuits - active components: integrated circuits - packaging – epoxy resins and quartz powder


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