Precision Power Scope combines power meter and oscilloscope

Terry Marrinan, Yokogawa's Vice President of Test & Measurement for Europe & Africa, comments: "As more and more innovation focuses on energy efficiency and the integration of electronics into power-based systems, more and more engineers are demanding accuracy and precision from their power measurement. With the launch of the PX8000, R&D professionals need no longer compromise on their need for high-accuracy time-based power measurement - a need that conventional power analysers and oscilloscopes were never designed to meet."

The PX8000 offers a combination of measurement accuracy, stability and repeatability, together with ease of use thanks to features familiar to users of Yokogawa's existing families of power analysers and oscilloscopes.

Power measurement capability

The new instrument has 12-bit resolution with 100MS/s sampling and 20MHz bandwidth. This means that the PX8000 can be used for accurate measurement of inverter pulse shapes, which can then be used to fine-tune inverter efficiency. A choice of input modules covers voltage, current and sensor measurements at voltages up to 1000V RMS and currents up to 5A RMS (higher values are possible with external current sensors), with basic accuracy down to +/-0.1 per cent.

To evaluate three-phase electrical systems, at least three power measurement inputs are required; the PX8000 not only has four inputs but also enables the simultaneous capture and display of voltage and current across all three phases.

Measurement and analysis of transient power profiles

In addition to delivering precision power measurement to give true insight into energy consumption and performance, the PX8000 incorporates a number of innovative features that support the crucial measurement and analysis of transient power profiles. It provides simultaneous voltage and current multiplication to give real-time power sampling, supporting both transient measurement (as standard) and numerical values averaged across the sample period. Up to 16 different waveforms - including voltage, current and power - can be displayed side-by-side, giving engineers instant 'snapshots' of performance.

The PX8000 is powered by Yokogawa's isoPROTM technology, which offers excellent isolation performance at very high speeds. isoPRO core technology, designed with energy-saving applications in mind, delivers the performance needed to evaluate high-efficiency inverters that operate at high voltages, large currents and high frequencies.

To enable cycle-by-cycle trends to be identified, the PX8000 has built-in functions for the direct calculation of derived parameters, such as root mean square (RMS) and mean power values.

Oscilloscope-style display

Yokogawa's new PX8000 provides graphical displays of voltage, current and power readings, which can be inspected for specific numerical values at any point or for calculating of average values over a specific period. The instrument also supports the capture of power waveforms over specific periods of time through the definition of start and stop 'cursors', which is particularly useful for examining transient phenomena and in the design of periodically controlled equipment. To ensure that such equipment complies with energy standards, it is vital to measure power consumption across a range of different modes from 'sleep' to full activity - and all the transient states in between.

The PX8000 also offers X/Y display capabilities that can be used, for example, to show the speed/torque characteristics of motors. It can also display Lissajous waveforms of input and output for phase analysis.

Power waveform recording

Like Yokogawa's digital oscilloscope family, the PX8000 incorporates a history memory function that automatically records up to 1000 historical waveforms that can be recalled and redisplayed at any time. Recorded waveforms can also used to redefine trigger conditions. Historical waveforms are explored via condition-based searches to locate specific hard-to-isolate abnormal phenomena during repeated high-frequency measurements.

A variety of functions including arithmetical calculations, time shifting and Fast Fourier Transforms (FFT) enable users to display waveforms with offsets and skew corrections. An automatic de-skewing function eliminates offsets between current and voltage signals that may be caused by sensor or input characteristics. Users can also define their own computations via equations that combine differentials, integrals, digital filters and a wealth of other functions.

Measure waveform harmonics

The PX8000 makes it possible to simultaneously measure the harmonic components of voltage and current waveforms as well as the harmonic distortion factor. Harmonic measurements take place in parallel with conventional voltage and current measurements. Harmonics up to the 500th order of the fundamental can be measured.

The PX8000 comes with the PowerViewerPlus PC software application that can be used to capture waveform data for further analysis. This dramatically extends the number of data points it is possible to analyse, making the PX8000 suitable for capturing and analysing longer-term performance. PC connection is via standard Ethernet/USB/GP-IB connections. The user-friendly software displays waveforms in a simple and clear graphical style that will be familiar to users of Yokogawa's popular Xviewer software. Researchers who want to use their own analysis software will be able to establish a connection to the PX8000 via the LabVIEW driver.

Applications and more information

Applications for the PX8000 cover everything from sustainable power to advanced robotics. Any situation where power consumption is at a premium - which means almost anywhere power is consumed - can benefit from the introduction of the PX8000 Precision Power Scope's measurement and analysis capabilities. Typical application sectors include inverter and motor testing, reactor loss measurement of inverter boost circuits, transient responses of industrial robots, wireless charger efficiency measurement, and voltage and power measurements in electricity distribution systems. Follow the link for more information about the PX8000 Precision Power Scope.