Yokogawa Announces: WT300 Series Digital Power Meter

Yokogawa announces its latest family of Digital Power Meters, the WT300 series. This new addition to Yokogawa’s highly recognized digital power analyzer product line is the 5th generation of its high performance, low cost product group. It offers updated and innovative measurement functions, which will benefit engineers with basic electrical power measurements. It is the ideal measurement solution for doing Stand-by-Power measurements, Energy Star® and IEC62301 testing, Battery Charger and other low level power measurements.

The WT300 family consists of three models: WT310, WT310HC, WT330. The WT310 is a single phase unit with the capability of measuring low currents from 50 micro-Amps up to 20 Amps RMS. The WT310HC is a single phase high current model with current ranges from 1 Amp to 40 Amps RMS. The WT330 is available as a two element or three element unit for applications on split phase and three phase circuits. This model has current ranges of 0.5 Amps to 20 Amps RMS. All models have voltage ranges from 15 to 600 Volts RMS.

Many of today’s power conversion circuits use energy saving switching techniques, which can cause highly distorted voltage or current waveforms with high harmonic content. To measure these waveforms accurately, the WT300 uses high resolution sixteen bit Analog to Digital converters with a digitizing rate of 100 kS/s, and a bandwidth from DC and 0.5 Hz to 100 kHz, (20 kHz on WT110HC). Basic power measurement accuracy is 0.1% of Reading plus 0.1% of Range. Measured data is displayed on four easy to read 7-segment LED displays.

An optional Harmonic Analysis function is available for the WT300 Digital Power Meter series. This function benefits the design and test engineer in product performance evaluation and power quality conformance testing. Both the Normal power parameters and Harmonic data are measured simultaneously, providing for faster and more accurate power analysis. Harmonic Analysis and THD Calculations can be made up to the 50th order from a 50 or 60 Hertz fundamental frequency.

The Integration function measures Amp-Hour and Watt-Hour parameters. A new Auto Range feature has been added to the Integration, which is especially important for stand-by-power measurements. In the stand-by mode the current can be very low. Then when the device goes to operation mode, the current can increase substantially. The new Auto Range feature optimizes the range setting for maximum accuracy measurements. Yokogawa’s “Average Active Power” function makes it possible to measure power consumption under conditions where the power fluctuates greatly. Watt-hours are measured over some time period, then the time is divided out to leave an average power reading. This is the preferred method for Stand-by-Power measurements.

All industry standard communication interface ports such as USB, GPIB, RS232C and Ethernet are available for the WT300 Series of Power Meters. The standard interface is USB plus GPIB or RS232C, with Ethernet as an available option. Yokogawa’s WTViewer Free Plus software is provided with each WT300 unit. IEC62301 software for stand-by-power measurements is also available as a free download.

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