Class S Power Quality Analysers offer a high level of accuracy and are typically used for statistical power quality surveys and for applications to make measurements needed for contractual compliance with standards where there are no disputes.
Class S defines the measurement time accuracys (better than +/- 0.3 sec/day) for parameters such as voltage, current and harmonics. With defined measurement methods and uncertainties for Power Supply Voltage, Voltage Fluctuations (Flicker). Voltage and Current Harmonic measurement methods and uncertainties in accordance with IEC 61000-4-7 Class I. The accuracy and performance requirements for Class S are not as strict as Class A.