Yokogawa Announces WT300 Digital Power Meters

January 11, 2013. Yokogawa has announced its latest family of digital power meters, the WT300 Series. This new addition to Yokogawa’s digital power analyzer product line is the 5th generation of its high-performance, low-cost product group. It offers updated measurement functions, which will benefit engineers making basic electrical power measurements. It is suitable for doing standby-power measurements, Energy Star and IEC62301 testing, and 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 µA up to 20 A RMS. The WT310HC is a single-phase high-current model with current ranges from 1 A to 40 A 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 A to 20 A RMS. All models have voltage ranges from 15 to 600 V 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 16-bit ADC 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 seven-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-Hz fundamental frequency.

The Integration function measures A-Hr and W-Hr parameters. A new autorange feature has been added to the Integration, which is useful for stand-by-power measurements. In the standby mode the current can be very low. Then when the device goes to operation mode, the current can increase substantially. The new autorange 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. W-Hrs are measured over some time period, then the time is divided out to leave an average power reading.

Iindustry standard communication interface ports such as USB, GPIB, RS-232C, and Ethernet are available for the WT300 Series of meters. The standard interface is USB plus GPIB or RS-232C, with Ethernet as an available option. Yokogawa’s WTViewer Free Plus software is provided with each WT300 unit. IEC62301 software for standby power measurements is also available as a free download.

The basic price for the single-phase WT310 is $2210. The three-phase WT330 starts at $3875.

Yokogawa, tmi.yokogawa.com