1 DC excitation constant current source input end is connected with the electromagnet, the current size of the conditioning input electromagnet, the magnetic induction intensity electromagnet changes in the gap size; 2 the InSb (InSb) magnetoresistive sensor and resistance box series, and is connected with the adjustable DC power supply, digital voltage meter connection end of magnetoresistive sensor resistance box is connected with the common contact, the knife edge and the other end of the single pole two-way switch. 3 conditioning after the electromagnet current, voltage and current measurement after InSb magnetosensitive sensor value and magnetoresistive devices at both ends of the resistance value, the magnetoresistive sensor value R, calculate the delta R/R (0) and B connection.Dongguan Jincheng Industrial Co., Ltd. is a research and development, manufacturing, sale of tension control, magnetic damper, as one of the professional manufacturers, the main production: tension device series, magnetic damper series, tension device, magnetic damper, magnetic damper damper, damper, and other goods. Www.www.swlawyer.org.cn