Multifunction Integra 1630 digital metering systems provide high accuracy
0.2% measurement, display and communication of all major electrical
and power quality parameters including total harmonic distortion (THD)
measurement up to the 31st harmonic. To suit user requirements, the range
includes single-phase, 3-phase 3-wire and 3-phase 4-wire capability, all
selectable at the point of installation.
Specification >> http://www.crompton-instruments.com/integra/integra_1630_datasheet.pdf