... field measurement, adopting the latest digit Ⅰ. Introduction ETCR3000 Digital Earth Resistance Tester is specially designed and manufactured for field ... Max,820Hz Voltage to ground--average value rectification.5.Data Mode Average value, maximum, minimum.6.Wire Resistance ... .with RS232 Interface to upload the testing data, with the fuction of Data Storage,Data Hold, Overflow Display,Alarm Function.17. ...