It exerts influence on the magnetic particle of the action territory, it is actualized and/or by the device which detects the said magnetic particle. As for the particular device, being the selective expedient which generates the magnetic field for selection, as for the magnetic field for the aforementioned selection, it possesses the kind of pattern where the small 1st sub territory of magnetic field strength and the big 2nd sub territory of magnetic field strength are formed inside the aforementioned action territory in inside the said magnetic field strength space, the aforementioned 1st territory inside the aforementioned action territory with selective expedient and the expedient of the magnetic field for drive and being the drive expedient which changes the position of the 2nd territory, and the reception expedient which acquires the signal, the said signal to depend on the magnetization inside the aforementioned action territory, as for the said magnetization the description aboveThe 1st sub territory and the influence with the change of position of the 2nd sub territory is received, it possesses reception expedient. The aforementioned reception expedient 1st compensating expedient and has 2nd compensating expedient, the said 1st compensating expedient and 2nd compensating expedient has the respective compensating coil.作用領域の磁性粒子に影響を及ぼし、及び/又は該磁性粒子を検出する装置によって実現される。当該装置は、選択用磁場を発生させる選択手段であって、前記選択用磁場は、該磁場強度空間内において、磁場強度の小さな第1サブ領域及び磁場強度の大きな第2サブ領域が前記作用領域内に生成されるようなパターンを有する、選択手段、駆動用磁場の手段によって前記作用領域内における前記第1領域及び第2領域の位置を変化させる駆動手段、並びに、信号を取得する受信手段であって、該信号は前記作用領域内の磁化に依存し、該磁化は前記第1サブ領域及び第2サブ領域の位置の変化による影響を受ける、受信手段を有する。前記受信手段は第1補償手段及び第2補償手段を有し、該第1補償手段及び第2補償手段はそれぞれ補償コイルを有する。
