... , 1A and 10A) can automatically change gears. 4. Actual loading calibration of watt-hour meters with three-phase four-wire ... or active, reactive errors of a multifunction meter, also can calibrate watthour meter and varhour meter. 7. Output electric energy constant can be ... clamp meter with 5A, 10A, 100A, 200A, 500A, 1000A, 2000A current span or flexible coil mutual inductor to realize actual loading ...