To measure the spread of lightning strikes or power outages, power quality should be measured at multiple points under the same time clock.
Model PW3198 can synchronize its time clock to the UTC (Coordinated Universal Time) clock with ±2ms accuracy by using the optional PW9005 GPS Box.
This allows you to measure power quality under the same time clock at any location. In addition, the PW3198 conforms to Class A performance of the IEC61000-4-30, so that the measurement results are within accuracy for all units
Source : Guidebook for Power Quality Measurement, HIOKI E.E. Corporation