Object-Property-Based Differential Eddy Current Gap Sensing Device

Author

Luheng Wang

Author_Institution

Coll. of Inf. Sci. & Eng., Northeastern Univ., Shenyang, China

Volume

36

Issue

1

fYear

2015

fDate

Jan. 2015

Firstpage

65

Lastpage

67

Abstract

To improve the sensitivity of thin eddy current device to measure the gap in small interlayer structure, an object-property-based differential structure is designed. The object-property-based differential eddy current gap sensing device has negative lift-off effect element (NLOEE) and positive lift-off effect element (PLOEE). The object in NLOEE/PLOEE is made of soft-magnetic material/nonmagnetic or hard-magnetic material, which results in a reduction/an increase of the NLOEE/PLOEE coil inductance with the increaese of the lift-off. Through using NLOEE and PLOEE as the neighboring arms of an electrical bridge, the conversion from the lift-off to the voltage is realized. The results show that the sensitivity can be improved using the object-property-based differential structure.

Keywords

coils; eddy currents; electric current measurement; electric sensing devices; inductance measurement; permanent magnets; soft magnetic materials; NLOEE; PLOEE; coil inductance; electrical bridge; hard-magnetic material; negative lift-off effect element; object-property-based differential eddy current gap sensing device; positive lift-off effect element; small interlayer structure; soft-magnetic material-nonmagnetic material; Bridge circuits; Coils; Eddy currents; Inductance; Materials; Sensitivity; Sensors; Differential structure; Eddy current effect; Gap sensing device; differential structure; eddy current effect;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2014.2369825

Filename

6954416