Martindale et5 200a ac dc electrical tester martindale et5 p martindale s et5 is a compact electrical tester that measures ac and dc voltage and current as well as resistance frequency and continuity and can take simultaneous measurement of current voltage and frequency voltage p p the tester can be used as a non contact voltage indicator and has auto ranging display hold and auto power off functions the et5 benefits from the additional features of capacitance temperature and duty cyc