NMI M 6-1 Electricity Meters. Part 1: Metrological and Technical ...
Minor corrections to applicable standards in A.2.9 and A.2.14 and .... Some of the
reference conditions and test requirements for class 1.5 meters have been ... A
device or function within the meter that is not part of the basic metrology function.
...... Frequency. 50 Hz. ±0.3%. ±0.3%. ±0.3%. ±0.3%. Phase sequence. L1-L2-L3.