Power meter gains more functionality

Featuring higher accuracy, new measurement functionality and improved connectivity – including Modbus/TCP capability – to aid integration into production environments.

 

The new WT300E series has a basic power accuracy of ±0.15% at 50/60 Hz on all measurement ranges, along with a bandwidth of DC and 0.1 Hz to 100 kHz. The influence of power factor is also greatly reduced: at low power factor the accuracy is twice that of the previous models (±0.1% of apparent power S).

 

The WT300E series covers a broad range of input currents from a few milliamperes up to 40 A RMS, making it suitable for measuring low currents in standby power testing as well as the high currents encountered in induction cookers. It can also measure waveforms with both AC and DC content.

 

There are four models in the range.  The WT310E single phase (including extremely low-current measurement capability down to 50 µA); WT310EH single phase high current; WT332E two-element; and WT333E three-element.

 

The instruments are said to be particularly suited to measurements on power conversion circuits using energy-saving switching techniques, which can cause highly distorted voltage or current waveforms with high harmonic content. They also have a new enhanced low-frequency measurement capability of 0.1 Hz in addition to the upper bandwidth limit of 100 kHz.

 

An optional harmonic analysis function is available which provides simultaneous measurement of both the normal power parameters and harmonic data for faster and more accurate power analysis. Harmonic analysis and total harmonic distortion calculations can be made up to the 50th order from a 50 or 60 Hz fundamental frequency.

 

An ‘average active power’ function makes it possible to measure power consumption under conditions where the power fluctuates. With this system, watt-hours are measured over a time period, and the time is divided out to give an average power reading. A new feature has been added to the data update rate. The WT300E series can follow fluctuating input frequencies, which typically occur in motor applications, by changing the data update rate automatically. Starting from the lowest 0.1 Hz input, this function can will detect cycles of the input signal automatically and measure it correctly.

 

All the industry standard communication interface ports such as USB, GPIB, RS232 and Ethernet are available for the WT300E series. The standard interface is USB plus GPIB or RS232, with Ethernet as an available option. Measured digital data from the WT300E series can be acquired by Yokogawa recorders via Modbus/TCP, aiding integration into production environments.

 

For further information about the WT300E visit tmi.yokogawa.com