... Digital Earth Resistance Tester is specially designed and manufactured for field measurement, adopting the latest digit Ⅰ. Introduction ... reliability for prolonged measure, which is widely used in electric power, telecommunications, meteorology, oil field, construction, lightning protection, industrial ... 3,Wireless frequency electromagnetic field≤1V/m 18.Protection Type IEC61010-1,IEC1010-2-31,IEC61557- ...