HZ-3521A three-phase watt-hour meter field calibrator is specially designed for on-site inspection of high-voltage power grid metering devices and fault detection. The instrument USES high-precision internal transformer and clamp type transformer for sampling, so that operators can quickly, safely and reliably measure meter recording errors and wiring errors. It provides an effective basis for electric power system inspectors to check electric theft and leakage, find out the failure of metering device, measure correctly and recover electric quantity.













