Benchtop power analyser from Yokogawa

The compact size, high speed and accuracy of the WT500 will make it attractive for quality-assurance purposes to manufacturers of power conversion equipment, including alternative energy sources such as photovoltaic generators, fuel cells and wind generators. It is also ideally suited to the measurement of bought and sold power in photovoltaic and other independent generation systems.

The WT500 will measure voltage, current, power and total harmonic distortion with a high update rate. Its three input channels, with inputs that can be set independently to measure different parameters and ranges, make it ideally suited to AC or DC measurements of input/output conversion efficiency in equipment such as invertors, drives and transformers.

The optional harmonic measurement functions can be used to measure the harmonic components of the voltage, current and power as well as the normal (total) measurement values. In addition, the RMS voltage and current (the total of the RMS values of all the frequency components in the measurement frequency bandwidth) can be measured simultaneously with the harmonic measurements.

The WT500 is designed for ease of use, with a set-up key accessing a range of pull-down menus. The ease and speed with which functions and set-up parameters can be accessed is a major advantage in efficiency measurements in a production-line environment.

Easily accessed functions include range selection, scaling, synchronisation source, line and frequency filters, update rate, averaging, and integration. The WT500 can integrate the active power (watt-hour), the current (ampere-hour), the apparent power (volt-ampere-hour) and the reactive power (VAR-hour). During integration, the measured and computed values of normal measurements can be displayed in addition to the watt-hour, current-hour, volt-ampere-hour, VAR-hour, sold/bought power and integration time.

Other features include user-defined functions, frequency measurement, harmonics setting and delta computation. In addition, a ‘miscellaneous’ key displays a menu for system overview, setting the date/time, selecting the message language, selecting the menu language, setting the display colour and setting the self-test function. A remote-control function is also available via the standard USB and optional GP-IB and Ethernet interfaces, while a store function is used to save directly to an external USB memory.