Yokogawa WT333E Digital Power Meter

The Yokogawa WT333E is a precision digital power meter engineered for AC and DC power measurements across R&D, production testing, quality assurance, and device evaluation environments. It delivers basic accuracy of ±(0.1% of reading + 0.05% of effective value measuring range) or ±0.15% of reading at 50/60 Hz, with simultaneous measurement of RMS, MEAN, and DC voltage alongside harmonic components and THD. The instrument supports multiple wiring configurations - single-phase three-wire, three-phase three-wire, three-phase four-wire, and three-voltage three-current - making it adaptable to diverse power distribution topologies.

Technical Specifications

Measurement Range & Accuracy

• Voltage: 6 ranges from 15 V to 600 V RMS; up to 1200 V RMS with modified range (1000 V RMS maximum input)


• Current: 6 ranges from 0.5 A to 20 A direct input; down to 50 µA with specified accuracy; 5 mA minimum range with 100 µW resolution


• Frequency bandwidth: DC, 0.1 Hz to 100 kHz for both voltage and current


• Sampling rate: 100 kS/s


• Crest factor: Measurable up to 300× in all ranges


• Data update rate: 100/250/500 ms/1/2/5/10/20 s, Auto selectable External Sensor Inputs


• EX1 channel: 2.5 V, 5 V, 10 V ranges


• EX2 channel: 50 mV, 100 mV, 200 mV, 500 mV, 1 V, 2 V ranges Harmonics & Integration


• Harmonic measurement: Up to 50th order (requires /G5 option)


• THD calculation: Included with harmonics analysis; PLL synchronization supported


• Integration time: Up to 10,000 hours with measurements for energy (Wh) and current (Ah); automatic range setting in integration mode

Key Features

• ±0.15% basic accuracy at fundamental frequency


• Simultaneous multi-parameter acquisition


• High-speed automatic ranging during integration


• Selectable data update rates from 100 ms to 20 s

Typical Applications

• Power supply characterization and efficiency testing


• Motor and drive evaluation


• Home appliance energy auditing


• Automotive electronics power profiling


• Manufacturing quality control and acceptance testing

Compatibility & Integration

• USB (standard)


• GPIB/IEEE-488 or RS-232-C selectable (-C2 option)


• Ethernet with Modbus/TCP (-C7 option)


• WTViewerE free PC application for parameterization, control, and data acquisition


• WTViewerFreePlus for monitoring and logging up to 200 parameters