1 need to be a sensor fixed on the magnet gap, no bending. 2 don't positioned adjacent with magnetic items in experimental instrument. 3 there shall be no external sensor supply. 4 boot preheat for 10 minutes, then the experiment. Should be more than 200 ohm to 5 external resistors. 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.pk-kicks.com