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              GDDO-20C AC/DC Electric Meter Calibration DeviceGDDO-20C AC/DC Electric Meter Calibration Device is used to detect basic error of various power frequency electric instruments in power systems, including voltmeter, ammeter, wattmeter, ohmmeter, single phase & three phase AC energy meters (optional) and basic error of DC volt-meter and ammeter. 
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              GDYM-3F Portable Multi-functional Energy Meter CalibratorSimultaneously test two detected pulse, and the constant, working mode and number of detected pulses at the same time can be totally different. 
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              GDYM-1A Single Phase Electric Energy Meter CalibratorGDYM-1A Single phase Electric Energy Meter Calibrator is multi-parameter measuring instrument which is full digital, mullti-function and high precision. 
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              GDYM-3M Multi-functional Electric Energy Meter CalibratorThe errors, voltage, current, active and reactive power, phase, frequency, and power factor can be measured simultaneously, also vector figure and wiring results will be displayed. 
