Double-core GMI current sensor

Author

Malatek, M. ; Ripka, P. ; Kraus, L.

Author_Institution

Fac. of Electr. Eng., Czech Tech. Univ., Prague, Czech Republic

fYear

2005

fDate

4-8 April 2005

Firstpage

1271

Lastpage

1272

Abstract

The design of a double-core giant magnetoimpedance (GMI) current sensor, which lowers the temperature influence and also improves linearity, is presented. The sensor consists of two ring cores made of 52 cm long CoFeSiBCr magnetoimpedance (MI) strips. In order to optimize the Ml characteristics, the ribbon was annealed at 390°C under axial field of 2400 kA/m. The sensor was driven by 1 MHz/5 mArms sinewave signal and the bias current I_b was 30 mA, corresponding to bias field of 80 A/m. Results show that the double-core sensor has smaller linearity error and temperature offset drift compared to single-core sensor. On the other hand, manufacturing of double core sensor is difficult, as suitable pair of magnetic cores with similar material properties should be selected, due to different magneto-impedance responses; hence the correction by detection electronics is usually needed.

Keywords

boron alloys; chromium alloys; cobalt alloys; electric current measurement; electric sensing devices; ferromagnetic materials; giant magnetoresistance; iron alloys; magnetic annealing; magnetic cores; silicon alloys; 30 mA; 390 degC; 52 cm; CoFeSiBCr; annealing; axial field; bias current; detection electronics; double-core current sensor; giant magnetoimpedance; linearity error; sinewave signal; temperature offset drift; Linearity; Magnetic cores; Magnetic sensors; Magnetic separation; Sensor phenomena and characterization; Strips; Temperature dependence; Temperature distribution; Temperature sensors; Toroidal magnetic fields;

fLanguage

English

Publisher

ieee

Conference_Titel

Magnetics Conference, 2005. INTERMAG Asia 2005. Digests of the IEEE International

Print_ISBN

0-7803-9009-1

Type

conf

DOI

10.1109/INTMAG.2005.1464065

Filename

1464065