digital earth resistance tester, with 2 pole, 3 pole, 4 pole to test earth resistance,soil resistivity,ac voltage SAT-10C ... . It could measure earth resistance and soil resistivity by 3-pole and 4-pole; also it could measure AC voltage.3. It should ... standard: ISO9001:2000Test item: Earth resistance Re by 2-pole, 3-pole and 4-pole Re range(Ω)Resolution(Ω)Accuracy0~19.990.01±(2%+2d ...