PROBLEM TO BE SOLVED: To configure devices accurately detecting fine magnetic fields at low costs and with simplicity.SOLUTION: A measurement device is provided that comprises: a plurality of measurement-purpose sensor units that is provided at a measurement position where a measurement object is measured, and detects input magnetic fields in a mutually different detection axis direction； a first conversion unit that converts outputs of the plurality of measurement-purpose sensor units to a plurality of measurement-purpose magnetic field signals indicative of a magnetic field direction in each coordinate axis direction； a plurality of reference-purpose sensor units that is provided at a reference position separated from the measurement position, and detects the input magnetic field in the mutually different detection axis direction； a second conversion unit that converts the output of the plurality of reference-purpose sensor units to a plurality of reference-purpose magnetic field signals indicative of the magnetic field direction in each coordinate axis direction； and a differential unit that calculates a plurality of differential signals indicative of a differential in each coordinate axis direction of the plurality of measurement-purpose magnetic field signals and the plurality of reference-purpose magnetic field signals.SELECTED DRAWING: Figure 7COPYRIGHT: (C)2020,JPO&INPIT【課題】微弱な磁場を精度よく検出する装置を、低コストで簡便に構成する。【解決手段】測定対象を測定する測定位置に設けられ、入力磁場を互いに異なる検出軸方向で検出する複数の測定用センサ部と、複数の測定用センサ部の出力を、各座標軸方向の磁場成分を示す複数の測定用磁場信号に変換する第１変換部と、測定位置から離間した参照位置に設けられ、入力磁場を互いに異なる検出軸方向で検出する複数の参照用センサ部と、複数の参照用センサ部の出力を、各座標軸方向の磁場成分を示す複数の参照用磁場信号に変換する第２変換部と、複数の測定用磁場信号および複数の参照用磁場信号の各座標軸方向の差分を示す複数の差分信号を算出する差分算出部とを備える、測定装置を提供する。【選択図】図７
