PROBLEM TO BE SOLVED: To provide a magnetic fluid detection element whose detectable distance is improved without being influenced by earth magnetism.SOLUTION: A magnetic fluid detection element includes: a rod-like soft magnetic ferrite 1 an AC excitation coil 2 wound around the rod-like soft magnetic ferrite 1 and magnetic sensors 3a and 3b which are arranged at both ends of the rod-like soft magnetic ferrite 1 and have magnetism detection sensitivity to an AC magnetic field component in the axis direction of the rod-like soft magnetic ferrite 1. An excitation magnetic field and a measurement magnetic field are converged and the magnetic fluid detection element is not influenced by earth magnetism in AC measurement by high permeability characteristics of the rod-like soft magnetic ferrite.COPYRIGHT: (C)2012,JPO&INPIT【課題】地磁気の影響を受けることなく、検出可能距離を向上した磁性流体検出素子を提供する。【解決手段】棒状軟磁性フェライト1と、棒状軟磁性フェライト1に巻かれた交流励磁コイル2と、棒状軟磁性フェライト1の両端に配置されて前記棒状軟磁性フェライト1の軸方向の交流磁界成分に対して磁気検出感度を有する磁気センサ3a、3bにより磁性流体検出素子を構成する。棒状軟磁性フェライトの高透磁率特性により励磁磁界および測定磁界の収束が行え、交流計測で地磁気の影響を受けない。【選択図】図1
