In 2001 DATEL introduced the ACA-20PC digital AC ammeters, the first ammeters to include a built-in current transformer. Their miniature size allowed them to be installed directly inside AC PDUs. ACA-20PC ammeters quickly grew to become Murata’s top DPM seller. While the ACA-20PC was only a single measurement device, the multi-measurement capability of the ACM20 Series is also suitable for new emerging markets, such as alternative energy instrumentation and residential energy monitors.