|Made with advanced technique by adopting large scale integrated circuit and highly reliable stepping motors etc. DDS523 single-phase electronic energy meters are the newest power counting products in our country to measure single phase AD active energy with the rated voltage of 220V and the rated frequency of 50Hz. This kind of products can precisely measure active energy both in positive and negative directions. It order to monitor and control active energy easily, it adopts testing signals with light-coupled output and light diodes to indicate the used power capacity. Its technical properties comform to IEC60521 standard.