Digital compass typically has the following characteristics: 1 three axis magnetic sensor measuring plane magnetic field, tilt compensation. 2 high speed and high precision A/D converter. 3 built-in temperature compensation, the maximum limit reduce tilt angle and temperature drift direction angle. 4 built-in microprocessor accounting angle sensor and magnetic north. I 5 has a simple useful user calibration instruction. 6 point with zero correction function. 7 shell structure waterproof, non magnetic. The principle of electronic compass is a measure of the earth's magnetic field, if there is a shield in addition to the earth outside of the magnetic field and magnetic field can not be useful in the use of the environment, so the use of electronic compass will have a lot of questions, then only thinking to determination of course using gyroscope. 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