... A 3.Multi-rate Digital display General introductionModel DDSF881 electronic single-phase multi-tariff watt-hour meter is used to measure ... life, high accuracy, good overload,low power consumption and small size. The meter adopts fault-tolerant technique to ensure calibration ... the relative technical requirements for class 1 single-phasewatt-hour meter in GB/T17215-2002 (IEC61036-2000), and its data ...