深圳灣邊貿易公司 TEL： 品名：地磁場磁強計 型號 Earth Magnetometer 2 工廠：AlphaLab, Inc. Product Description: The EM2 measures small variations from location to location in the Earth magnetic field associated with buried magnetic masses. Unlike metal detectors, a magnetometer signal is not attenuated by rock, dirt, mud or water, so targets can be detected at great depth. (If D is the diameter of a mass of magnetizable material, the EM2 can detect it as deep as 40 times the diameter D, whether the mass is specifically magnetized or not.) It is the lightest weight and lowest cost magnetometer available which can reliably measure differences down to 1 nT from point to point. (Because of random fluctuations in the Earth field due to the ionosphere, 1 nT is about the finest usable resolution.)