Cantilever-Type FePd/PZT Stacked-Layer Magnetic Sensors with High Sensitivity

2013 ◽  
Vol 96 (11) ◽  
pp. 8-15 ◽  
Author(s):  
Takashi Saito ◽  
Mio Hamashima ◽  
Chihiro Saito ◽  
Motoichi Nakamura ◽  
Teiko Okazaki ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Magnetic Sensors

scholarly journals A broadband two axis flux-gate magnetometer

1998 ◽  
Vol 41 (3) ◽  
Author(s):  
P. Palangio
Keyword(s):  
Magnetic Field ◽  
Low Frequency ◽  
High Sensitivity ◽  
Magnetic Sensors ◽  
Frequency Range ◽  
Field Station ◽  
Low Weight ◽  
Highly Sensitive ◽  
Flux Gate ◽  
Magnetic Field Variations

A broadband two axis flux-gate magnetometer was developed to obtain high sensitivity in magnetotelluric measurements. In magnetotelluric sounding, natural low frequency electromagnetic fields are used to estimate the conductivity of the Earth's interior. Because variations in the natural magnetic field have small amplitude(10-100 pT) in the frequency range 1 Hz to 100 Hz, highly sensitive magnetic sensors are required. In magnetotelluric measurements two long and heavy solenoids, which must be installed, in the field station, perpendicular to each other (north-south and east-west) and levelled in the horizontal plane are used. The coil is a critical component in magnetotelluric measurements because very slight motions create noise voltages, particularly troublesome in wooded areas; generally the installation takes place in a shallow trench. Moreover the coil records the derivative of the variations rather than the magnetic field variations, consequently the transfer function (amplitude and phase) of this sensor is not constant throughout the frequency range 0.001-100 Hz. The instrument, developed at L'Aquila Geomagnetic Observatory, has a flat response in both amplitude and phase in the frequency band DC-100 Hz, in addition it has low weight, low power, small volume and it is easier to install in the field than induction magnetometers. The sensivity of this magnetometer is 10 pT rms.

THE QNDE USING IMAGE PROCESSING OF THE MAGNETIC CAMERA

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4625-4630 ◽  
Author(s):  
JINYI LEE ◽  
JISEONG HWANG ◽  
SEHO CHOI
Keyword(s):  
Image Processing ◽  
High Speed ◽  
Magnetic Hysteresis ◽  
High Sensitivity ◽  
Magnetic Sensors ◽  
Second Derivatives ◽  
Crack Volume ◽  
Lift Off ◽  
Magnetic Camera ◽  
Derivatives Of

A scan type magnetic camera was proposed to satisfy the following demands: to obtain high speed quantitative magnetic flux leakage (MFL) distribution with homogeneous lift-off by using 2-dimensionally arrayed high sensitivity magnetic sensors; to concentrate the MFL; and to ignore the residual magnetization and magnetic hysteresis by using a magnetic fluid lens. The magnetic field distribution (MFD) image obtained by using the scan type magnetic camera is inclined to the scanning direction (x-direction) because of the poles of the magnetizer. Also, the image shows a homogeneous trend relative to the x-direction, but there are small waves in the distribution in the sensor arraying direction (y-direction). The crack information in the MFD image can be extracted using image processing. The first and second derivatives of both x and y are used in this processing. These are "1st derivative of x, ∂B/∂x", "1st derivative of y, ∂B/∂y", "2nd derivative of x, ∂2B/∂x2", "2nd derivative of y, ∂2B/∂y2", and "2nd derivative of x and y, ∂2B/∂x∂y". The ∂B/∂x distribution shows the existence of the crack. Also, the crack volume can be evaluated quantitatively, regardless of the crack direction, by using ∂B/∂x and a cross type magnetic coil.

High Sensitivity Hall Magnetic Sensors Using Planar Micro and Macro Flux Concentrators

2001 ◽  
pp. 160-163 ◽  
Author(s):  
Predrag M. Drljaca ◽  
Vincent Schlageter ◽  
Franck Vincent ◽  
Radivoje S. Popovic
Keyword(s):  
High Sensitivity ◽  
Magnetic Sensors

High sensitivity pressure transducer based on the phase characteristics of GMI magnetic sensors

2018 ◽  
Vol 29 (3) ◽  
pp. 035106 ◽  
Author(s):  
L S Benavides ◽  
E Costa Silva ◽  
E Costa Monteiro ◽  
C R Hall Barbosa
Keyword(s):  
Pressure Transducer ◽  
High Sensitivity ◽  
Magnetic Sensors

High-Sensitivity Tunnel Magnetoresistance Sensors Based on Double Indirect and Direct Exchange Coupling Effect*

2021 ◽  
Vol 38 (12) ◽  
pp. 128501
Author(s):  
Xiufeng Han ◽  
Yu Zhang ◽  
Yizhan Wang ◽  
Li Huang ◽  
Qinli Ma ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Noise Level ◽  
Exchange Coupling ◽  
Coupling Effect ◽  
High Sensitivity ◽  
Wheatstone Bridge ◽  
Low Noise ◽  
Magnetic Sensors ◽  
Tunnel Magnetoresistance ◽  
Current Detection

Abstract Detection of ultralow magnetic field requires magnetic sensors with high sensitivity and low noise level, especially for low operating frequency applications. We investigated the transport properties of tunnel magnetoresistance (TMR) sensors based on the double indirect exchange coupling effect. The TMR ratio of about 150% was obtained in the magnetic tunnel junctions and linear response to an in-plane magnetic field was successfully achieved. A high sensitivity of 1.85%/Oe was achieved due to a designed soft pinned sensing layer of CoFeB/NiFe/Ru/IrMn. Furthermore, the voltage output sensitivity and the noise level of 10.7 mV/V/Oe, 10 nT/Hz1/2 at 1 Hz and 3.3 nT/Hz1/2 at 10 Hz were achieved in Full Wheatstone Bridge configuration. This kind of magnetic sensors can be used in the field of smart grid for current detection and sensing.

Research Status and Development of the Circuit System of Giant Magneto-Impedance Sensor

2014 ◽  
Vol 494-495 ◽  
pp. 951-954 ◽  
Author(s):  
Xiu Sheng Duan ◽  
Jing Xiao
Keyword(s):  
Data Processing ◽  
High Sensitivity ◽  
Magnetic Sensors ◽  
Harsh Environment ◽  
Measuring Range ◽  
Good Reliability ◽  
Practical Solution ◽  
New Type ◽  
Giant Magneto Impedance ◽  
Impedance Sensor

Giant Magneto-Impedance (GMI) sensor is a new type of magnetic sensors. Comparing with traditional sensors, GMI sensor has the advantages of high sensitivity, good reliability, wide measuring range and small size and is potential in resisting harsh environment. In the paper, circuit systems both in overseas and domestic researches are analyzed, shortcomings of the systems are pointed out and some improvement ideas are presented. At last, elaborate the development trends of GMI sensor's circuit system to find a practical solution for data processing technology.

Multilayered Magnetic Wires and Films for Electromagnetic Sensor Technology

2008 ◽  
Vol 54 ◽  
pp. 29-40
Author(s):  
Larissa V. Panina ◽  
D.P. Makhnovskiy ◽  
Arkadi Zhukov ◽  
J. Gonzalez
Keyword(s):  
Data Storage ◽  
High Sensitivity ◽  
Magnetic Sensors ◽  
Soft Magnetic Materials ◽  
Sensor Technology ◽  
Strong Impact ◽  
Impedance Change ◽  
Destructive Testing ◽  
Multilayered Structures ◽  
Sensing Applications

The discovery of the magnetoimpedance (MI) effect in 1994 had a strong impact on the development of magnetic sensors, offering miniature, highly sensitive, and quick response elements. Along with traditional areas of sensing applications (data storage, bio-medical electronics, robotics and security), the MI elements have a high potential for non-destructive testing (as eddy current probes) and smart sensory systems (self-sensing composites). In certain soft magnetic materials, such as composites of amorphous thin wires, the impedance change (MI ratio) can be as high as 600 % in the MHz band and 50-100% at GHz frequencies subjected to small magnetic fields or stresses. Furthermore, special thin-film structures have been proposed to improve the MI performance in miniature elements. This paper discusses physical concepts of MI in multilayered structures including MI ratio enhancement and effect of anisotropy, experimental results proving high sensitivity to the external stimuli for excitation frequencies up to few GHz, practical sensor designs and, finally, the use of MI fibers for tagging the composites to build-in sensing functionality .

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