Presentation is loading. Please wait.

Presentation is loading. Please wait.

MAGNETOMETRY Theoretical and experimental research

Similar presentations


Presentation on theme: "MAGNETOMETRY Theoretical and experimental research"— Presentation transcript:

1 MAGNETOMETRY Theoretical and experimental research
0onv Baltag Octavian Ioan Ligns of force of the geomagnetic field (Glatzmaier et Roberts, 1995).

2 1971 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 THEORETICAL AND APPLICATIVE RESARCH IN MAGNETOMETRY DIRECTIONS 1971 - 2001
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 ELECTROMAGNETIC COMPATIBILITY Special applications Research & industry METROLOGY, TRANSDUCERS & SPECIAL DEVICES PROTECTION OF INTELECTUAL & INDUSTRIAL PROPERTY Patents Trademarks

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

5 MAGNETOMETRY Theoretical & experimental research on the fluxgate transducers for low magnetic field Iex h ferrofluid h Hex U2f Iex h h Hex h + Hex h - Hex U2f h I ex h U2f Iex

6 Fluxgate diagram H B +Bs H t -Bs d/dt H=H0sint h=0 h>0 U2f
Core I Core II U2f H

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 FLUXGATE WITH MULTIPLE PATH OF FLUX patent RO, nr. 60. 346, Int. Cl
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 FLUXGATE WITH MULTIPLE PATH OF FLUX patent RO, nr. 60. 346, Int. Cl
FLUXGATE WITH MULTIPLE PATH OF FLUX patent RO, nr , Int. Cl. G01R33/00

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 Fluxgate – nonlinear resonance
Transfer characteristic U2ω = f (h) of the fluxgate in second harmonic resonance regime U2f second harmonic amplitude H external magnetic field Uex excitation voltage f excitation frequency Hysteresis response to applied field of the fluxgate on second harmonic: UQ second harmonic quadrature component US second harmonic, sinphasic component UA second harmonic amplitude H external magnetic field

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 DOUBLE PUMPING MAGNETOMETER Patent RO, no. 67520, Int. Cl. G01R33/02
Fluxgate responses U2f (second harmonic 2f) at second pumping field F=200Hz, and measuring field Ho Second harmonic U2f 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 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 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 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. 1998 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 ELECTRONIC CIRCUITS FOR FLUXGATE MAGNETOMETER
Electronic devices for fluxgate excitation and generating of reference signal, Patent RO., No (1982), Int. Cl. G01G33/02

18 ELECTRONIC CIRCUITS FOR FLUXGATE MAGNETOMETER
Reference 2f Frequency divider 1/2 Synchro-nous Detector Phase shift Selective amplifier Excitation generator Generator 2f f D.C. Amplifier Negative feedback circuit Negative feedback network Excitation Generator S Ue h hr ir Ur Feedback coil Ku , Ki , rr Ur = Ue Us Reference 2f

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


Download ppt "MAGNETOMETRY Theoretical and experimental research"

Similar presentations


Ads by Google