Transcript MAGNETOMETRY Theoretical and experimental research Baltag Octavian Ioan Ligns of force of the geomagnetic field (Glatzmaier et Roberts, 1995). http://paleomag.uqar.ca/spip.php?article44

MAGNETOMETRY
Theoretical and
experimental research
Baltag Octavian Ioan
Ligns of force of the geomagnetic field (Glatzmaier et Roberts, 1995).
http://paleomag.uqar.ca/spip.php?article44
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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
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THEORETICAL AND APPLICATIVE
RESARCH IN MAGNETOMETRY
DIRECTIONS 1971 - 2001
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MAGNETOMETRY
Space applications
Marine applications and naval
degaussing
Terrestrial – special applications
Laboratory – research & industry
METROLOGY,
TRANSDUCERS & SPECIAL
DEVICES
MAGNETIC DETECTION
 Magnetic naval and
terrestrial mines
 Industrial applications buried metallic bodies
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ELECTROMAGNETIC
COMPATIBILITY
Special applications
Research & industry
PROTECTION OF INTELECTUAL & INDUSTRIAL PROPERTY
 Patents
 Trademarks
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RESEARCH DOMAIN 2001 - 2008
HIGH RESOLUTION MAGNETOMETRY
 Biomedical applications
MICROWAVE RADIOMETRY
 Microwave Thermografy – early detection of the
breast cancer
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MAGNETOMETRY
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Theoretical & experimental research on the fluxgate transducers for
low magnetic field
Iex ferrofluid
Hex
h
U2f
h
Iex
h
I ex
H
h+
Hex
h
ex
hHex
h
h
U2f
U2f
h
H
ex
Iex
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Fluxgate diagram
B
B
H
+Bs

H
t
-Bs
H=H0sint
d/dt
h=0
h>0
t
h>0
U2f
t
t
Core I
Core II
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RESULTS AND APPLICATIONS
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Research on the fluxgate
transducers & magnetometer
electronics – applications for
Intercosmos satellites
Technical data:
• range: +/- 80.000 nT
• frequency of pulse excitation: 2 kHz,
• second harmonic: 4 kHz
• noise: < 1 nT
• nonlinearity : < 1%
• applications: triaxial magnetometer
for Intercosmos satellites
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FLUXGATE WITH MULTIPLE PATH OF FLUX
patent RO, nr. 60.346, Int. Cl. G01R33/00
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Fluxgate sensor with multiple
path of flux, O. Baltag, D.
Costandache„ “Studies in applied
electromagnetics and mechanics”,
vol.13, pp.337-340, 1998, Editor:
V. Kose, J. Sievert, IOS PressAmsterdam, ISSN: 1383-7281
Specifications:
• Measuring range: +/- 200.000nT
• noise: < 1 nT
• excitation: pulse
• liniarity: < 1%
Core: permalloy processed by
photogravure, trated in hidrogen, coil
support: noril and cuartz powder
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FLUXGATE WITH MULTIPLE PATH OF FLUX
patent RO, nr. 60.346, Int. Cl. G01R33/00
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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.
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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
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Nonlinear resonance - Applications
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Double pumping magnetometer and
measuring method, patent Ro, No.
67520, 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
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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: +/- 200.000 nT
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FERROFLUID FLUXGATE TRANSDUCER
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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.263-265, ISBN: 0-7803-3312-8, IEEE Xplore, INSPEC Number:
5391810
Sensor with ferrofluid for magnetic measurements, O. Baltag, D. Costandache,
IEEE Trans. on Instrumentation and Measurement, vol. 46, nr.2, pp. 629-631,
1997
Nonlinear behaviour of the ferrofluid in orthogonal magnetic fields, O. Baltag, D.
Costandache, JMMM, 201, pp.123-125, 1999
The study of a magnetic fluid based sensor, C. Cotae, O. Baltag, R.Olaru,
D.Calarasu, D.Costandache, JMMM, 201, pp.393-397, 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: 0-7803-3376-4
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FERRITE FLUXGATE
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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
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AMORPHOUS AND NANOCHRISTALINE
FLUXGATE
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Preisach approach for modelling an
amorphous toroidal fluxgate sensor, A.
Salceanu, O. Baltag, D.Costandache,
Sensor and Actuators, A, vol. 81, pp.207-211,
1999, ISSN: 0925-4005
 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.381-384, 1999, ISSN 0258-9109
 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.665669, 2000, IOS Press-Amsterdam, ISSN:
1383-7281
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ELECTRONIC CIRCUITS FOR FLUXGATE MAGNETOMETER
Electronic devices for fluxgate
excitation and generating of
reference signal, Patent RO., No.
80140 (1982), Int. Cl. G01G33/02
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ELECTRONIC CIRCUITS FOR FLUXGATE MAGNETOMETER
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Negative feedback network
Negative
feedback
circuit
Selective
amplifier
Excitation
generator
f
Reference
2f
h
Frequency
divider 1/2
D.C. Amplifier
Phase
shift
Synchronous
Detector
Fluxgate
Generator
2f
Reference 2f
Us
Ue

S
Ur = Ue
Excitation
Generator
ir
hr

Ur
Feedback
coil
Ku , Ki , rr
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ELECTRONIC CIRCUITS FOR FLUXGATE MAGNETOMETER
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Integrated hybrids circuits for
magnetometry
- ceramics support
- resistors – laser trimming
- active components: integrated
circuits
- packaging – epoxy resins and
quartz powder
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