Abstract:Aimed at the problems existed in filteringgraphy method that wear particle distribution is irregular in the filter membrane and it is difficult to distinguish ferromagnetic particles and non ferromagnetic particles,a magnetic filteringgraphy instrument was designed,which adopts the automatic control mechanism so as to improve the work efficiency of the common filteringgraphy instrument,uses a permanent magnet in the bottom end of the filter to make the ferromagnetic particles in oil samples distribute along the direction of magnetic lines on filter membrane.The magnetic field strength and magnetic field direction of the magnetic filteringgraphy instrument were obtained through finite element analysis method.Experimental results show that the ferromagnetic particles is distributed along the direction of magnetic lines on the filter membrane obtained by magnetic filteringgraphy instrument,so they can be quickly distinguished from the non ferromagnetic particles,and the work efficiency and credibility are also improved.