Martindale cm69 60a ac true rms trms earth leakage current clamp meter martindale cm69 p the martindale cm69 is a high performance true rms ac earth leakage clamp meter with an outstanding low current capability allowing it to resolve down to 1 micro a the advanced jaw design minimises the influence of conductor position and shields against external fields from other conductors to give more accurate and consistent results p p earth leakage clamp meters operate by clamping around both the