Special double core structure. One core is for AC measurement, the other is for DC. AC measurement capacity is 20-30% bigger than listed range. DC measurement capacity is more than 71% of the listed AC measurement range. High accuracy, AC measurement accuracy up to class 0.5 or class 1.0. Typical meter measurement error after giving DC influence is at 0.5%-2% for 0.1class CT. Small phase error, typical phase shift is at 1-10; Additional compensation not needed Good isolation between Primary and Secondary Very reliable and stable performance at different temperature conditions Frequency: 50Hz/60Hz Ambient Temperature: -40oC -- 70oC