Measurement instruments for power quality monitoring

IEEE 1159 is a recommended practice for monitoring electric power quality. Among the clauses within this standard is a section describing the measurement instruments for power quality monitoring. Depending on the situation being addressed, or the survey being made, a variety of different measuring instruments could be used. For simple situations, a handheld multimeter or oscilloscope could suffice. For more involved situations, a dedicate power quality monitor might be required. No matter how sophisticated, each measuring instrument has limitations that should be considered. Often these limitations are imposed by the response of the voltage and/or current probes and transducers, external to the measurement device. This paper outlines these various issues that should be considered when selecting a measuring instrument for use to measure power quality and its influence in an electrical power system.