Characteristic Analysis and Enhancement of Sensing Property for Eddy-Current Type Proximity Sensor

Koichi KOIBUCHI
Koichiro SAWA
Takashi HONMA
Takumi HAYASHI
Kuniyoshi UEDA
Hiroshi SASAKI

Publication
IEICE TRANSACTIONS on Electronics   Vol.E88-C    No.8    pp.1696-1703
Publication Date: 2005/08/01
Online ISSN: 
DOI: 10.1093/ietele/e88-c.8.1696
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Section on Recent Development of Electro-Mechanical Devices--Selected Papers from International Session on Electro-Mechanical Devices 2004 (IS-EMD2004)--)
Category: Sensing Devices
Keyword: 
proximity sensor,  eddy current loss,  magnetic circuit,  numerical analysis,  finite element method,  

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Summary: 
An eddy-current type proximity sensor is a non-contact type sensing device to detect the approach of a conductor by increase of equivalent AC resistance of excitation coil due to eddy current loss in the conductor. In this paper, electromagnetic characteristics of the actual proximity sensor are calculated by FEM and the validity of numerical analysis results are studied. Furthermore, two models that has modified magnetic circuit geometry based on the actual sensor are designed and calculated as numerical experiments. Calculated results are shown as enhanced sensing index or electromagnetic characteristics of the modified sensor. In conclusions, knowledge about the magnetic circuit geometry of the sensor is applied for the enhancement of sensing property.