Inductive Type Wh-meters, which are based upon the principle of mechanically averaging instantaneous power measure electrical energy consumed in a home for billing purposes. It is guaranteed only commercial frequencies 50/60Hz.

1: current coil 2: Short ring
3: Movable disk 4: Phase adjusting coil
5: magnetic shunt steel 6: manganin resistor
7: Secondary voltage coil 8: Voltage coil

Principle : Repulsion of magnetic field caused by currents of both Fixed and Moving coils

Principle : Time Division Multiple analog circuit method Multiplication circuit Waveform

Restrictions ; High displaying resolution(whether it is enough to settled range.) Accuracy and Linearity in case of small input Influence of high frequency Common Mode Voltage

YOKOGAWA 2533

Principle : Digital filtering method of digital sampled data

Restrictions ; High displaying resolution(whether it is enough to settled range.) Dynamic ranges and accuracy especially both small and large current Fast response time(combination between measuring period and dead time)

YOKOGAWA WT2000