PX8000 Precision Power Scope

The PX8000 is the world's first precision power scope, bringing oscilloscope-style time-based measurement to the world of power analyzers. With up to four channels, it can perform standard multi-phase power measurements. These measurements exist alongside oscilloscope-specific features such as cursor-based specific time period measurements to enable analysis of waveforms with transient components.

Transient power measurements and analysis

The PX8000 has a number of innovative features that support the crucial measurement and analysis of transient power profiles. 

Simultaneous power calculation Provides simultaneous voltage and current multiplication to give real-time power sampling.
Cycle-by-cycle power trend measurement Trend measurements between waveforms can be calculated by mathematical functions (up to four million points). 
Specific time-period measurement Supports the capture of power parameters over specific periods of time through the definition of start and stop "cursors". 
Specified time-period waveform measurement Supports the capture of waveform parameters over specific periods of time through the definition of start and stop "cursors".
X-Y display and phase analysis Supports X-Y axis displays as standard. It can also display lissajous waveforms of input and output for phase analysis.
Capturing sudden or irregular phenomena An always-active History function automatically records up to 1,000 historical waveforms. 
Long-period data capture and analysis An accompanying PC application called PowerViewerPlus can be used to capture waveform data for further analysis. 
FFT analysis Features arithmetical, time-shift, FFT and other computations that enable users to display waveforms with offsets and skew corrections. 
Simultaneous harmonic measurement Makes it possible to simultaneously measure the harmonic components of voltage and current waves as well as the harmonic distortion factor. 
Multifunction snapshots Up to 16 different waveforms- including voltage, current and power, can be displayed side-by-side, giving engineers instant snapshots of performance. 
Detailed transient analysis Supports the measurement of all power waveform parameters between precisely defined start and stop cursors.
Trend calculation Built-in functions for the direct calculation of variables, such as root mean square (RMS) and mean power values, to enable the identification of cycle-by-cycle trends.
De-skew compensation Automatic de-skewing function eliminates offsets between current and voltage signals that may be caused by sensor or input characteristics.
Powered by isoPRO technology Offers industry-leading isolation performance at the highest speeds. Delivers the performance needed to develop high-efficiency inverters that operate at high voltages, large currents, and high frequency. 

The PX8000 is an immensely versatile instrument, unlocking precision power measurement capabilities for researchers working on everything from renewable power to advanced robotics. 

Inverter and motor testing

Electric and hybrid vehicles have many electrical and mechanical components, and overall performance evaluation requires measuring the efficiency of both. The PX8000's flexibility, accuracy and wide bandwidth make it ideal for drawing together the range of power readings needed to optimize the efficiency of boost circuits and inverters- two key elements in overall electric vehicle performance.

 

Wide bandwidth With a 12-bit resolution, 100 MS/s sampling, and 20MH bandwidth, the PX8000 can be used for accurate measurement of inverter pulse shaped, which can then be used to fine-tune inverter efficiency.
Transient measurement by cycle-by-cycle trend The ability to analyze cycle-by-cycle trends makes it ideal for the measurement of transient effects. When the load changes rapidly, engineers can gain insights that will enable them to improve the control of the inverter.
Harmonic and FFT analysis With both harmonic and FFT measurement capabilities, the PX8000 can measure fundamental waveforms from 20Hz to 6.4kHz. This is particularly useful for analyzing higher harmonic component and causes of noise in electromechanical systems.
Offset cancels by individual NULL function A common problem when testing inverter motors is the presence of ambient noise that can mean test values are nonzero even before testing begins. The PX8000's offset capabilities mean such effects can be nullified and specific inputs can be isolated for testing and analysis. 

Screen Shot 2014 01 09 At 4.26.18 PM

Reactor loss measurement of inverter boost circuits

A reactor is used to filter out noise and boost voltage levels prior to the use of an inverter. It consists of an electromagnetic material core and a coil. A main focus for electrical engineers is to reduce power loss across the total inverter system, and reactor performance is of particular interest. There are two potential evaluation methods: direct loss measurement of the reactor and iron loss measurement. The PX8000 supports either methodology because it can accommodate both high frequency measurement and low-power-factor conditions. 

 

Low-power-factor measurement Higher sampling rates and broad bandwidth make the PX8000 particularly useful for testing devices, such as transformers and reactors that have lower power factors. It is particularly important to measure the precise power consumption of such devices at high frequency.
De-skew functionality To analyze power consumption in low-power-factor devices it is particularly important to minimize any time differences between voltage and current caused by sensor input characteristics. The PX8000 provides precise de-skew adjustment to compensate for this time difference. 
Core loss measurement under high frequency Analyzing reactor core loss is an example of how the PX8000's user-defined functions can be utilized to provide an instant analysis of system performance. In the example below, core loss is calculated based on primary coil current and secondary coil voltage, while magnetic flux density (B) and magnetic field (H) are calculated by factoring in input frequency, cross-sectional area and other parameters. All values can be displayed directly by the PX8000. 

Screen Shot 2014 01 09 At 4.26.18 PM

Wireless charger efficiency measurement

The development of wireless charging technology for mobile devices like smartphones and tablet devices is a focus for research. Automotive manufacturers are looking into the possibility of charging electric vehicles wirelessly. Wireless charging depends on two electromagnetic coils being configured to support particular frequency profiles. Efficient power transfer and the prevention of power loss are naturally particularly important. The PX8000 is ideally suited for measuring such systems because of its ability to operate at high frequencies and low power factors.

 

Wireless charger efficiency evaluation To evaluate the efficiency of wireless transfer, at least three power measurement elements are required. The PX8000, with its four input channels, can analyze the performance of the whole system simultaneously.
Low-power-factor device measurement Higher sampling rates and broad bandwidth make it ideally suited for wireless power transfer systems. The PX8000 supports 12-bit resolution, sample rates of up to 100MS/s and a 20MHz bandwidth. The PX8000 supports the measurement of low-power-factor systems operating at very high frequencies.
 
De-skew functionality Because the PX8000 provides a de-skew function, differences between voltage and current that are introduced by sensor and input characteristics can be compensated for and eliminated from the analysis of low-power-factor systems. 
 

Screen Shot 2014 01 09 At 4.43.00 PM

Power distribution

Power distribution systems have to maintain constant voltage and constant power during load switching or in the case of a short circuit. Distribution protectors or circuit breakers for three-phase electrical systems must therefore be tested at transient voltage and power levels. The PX8000 can capture fluctuation voltage and current waveform, calculate power parameters (including voltage and current values), determine an average over a specified period and display all values.

 

Simultaneous three-phase data capture To evaluate three-phase electrical systems, at least three power measurement inputs are required. The PX8000 has up to four inputs and enables the simultaneous capture and display of voltage and current across all three phases.
Specific time-period measurement For a true evaluation of distribution protection, it is necessary to measure a full cycle of voltage current and power values half a cycle after the recovery from a short circuit. The PX8000 can easily be set up to focus on such a specific period.
Harmonic and FFT analysis The PX8000 has capabilities for both harmonic measurement and FFT for frequency analysis. The harmonic function can measure fundamental frequencies from 20Hz to 400kHz, and FFT has 1k to 100k points calculation across two channels. Such measurements are vital for identifying harmonic currents and identifying sources of noises. 

Screen Shot 2014 01 09 At 4.45.43 PM 1

 

Transient responses of industrial robots

To evaluate motor-driven robots, power consumption of all motors and controllers are measured throughout all operational speeds and action patterns. Design engineers need to measure inrush voltage, current and power over the pattern of repeated actions. Efficiency is calculated by comparing mechanical output with input power. During actual operating conditions, the time to accelerate and decelerate such motors can range from several hundred milliseconds to several seconds. As a PWM-driven motor rotates from the reset position to the top speed, the drive frequency from the rest position to the top speed, the drive frequency changes from DC to several hundred Hz. The PX8000 gives design engineers insight into power consumption and efficiency throughout a robot's operational performance. 

 

Specific time-period analysis Supports the measurement of waveform data between specific Start/Stop cursors. Combined with its multi-channel capabilities and its Long memory and History functions, this makes the PX8000 particularly useful in rating a robot's operational power consumption. 
Efficiency measurement of boosters, inverters and motors A single PX8000 unit can measure both the input/output power of inverters and the mechanical output of a motor. By installing three power units and one AUX module, the PX8000 can be configured to provide an instantaneous measure of component efficiency.
 
Transient measurement by trend computation With its instantaneous power calculations, the PX8000 is ideal for evaluation and optimizing transient effects. Its cycle-by-cycle trend analysis provides further insights into this crucial area of robotics engineering.
 
Longer time-period measurement To analyze some robotic operations, it may be necessary to perform cycle-by-cycle trend analysis over a long period of time. The PowerViewerPlus software extends this mathematical capability to enable deep insights to be obtained from the data.

Screen Shot 2014 01 09 At 4.39.37 PM

 

Long phenomena capture

The large internal memory of up to 100M Points enable long term measurements to be made at high and appropriate sample rates. 

PX8000_Connectivity

 

 

 July 12, 2017

  • Released firmware version 3.21

 February 10, 2017

  • Released firmware version 3.12

April 28, 2016

  • Released firmware version 3.11

November 19, 2015

  • Released sensor power supply option (/PD and dedicated accessories)

Ocober 22, 2014

  • Released dedicated software, PowerViewerPlus

December 4, 2014

Yokogawa

760811 Voltage Module

A Power Module consists of one Voltage Module- Model 760811, and one Current Module- 760812 or 760813.

760812 Current Module

A Power Module consists of one Voltage Module- Model 760811, and one Current Module- 760812 or 760813.

760813 Current Input Module

A Power Module consists of one Voltage Module- Model 760811, and one Current Module- 760812 or 760813.

760851 Auxiliary Module

Sensor and voltage measurement module (up to three modules can be installed) Auxiliary (AUX) module

366924 BNC to BNC 1m Cable

BNC-BNC 1m. For connection to simultaneously measurement with 2 units, or for input external trigger signal. 

366925 BNC to BNC 2m Cable

BNC-BNC 2m. For connection to simultaneously measurement with 2 units, or for input external trigger signal.

366926 BNC to Alligator 1m Cable, 1:1

A 1 m long BNC-alligator clip cable.
Use only for circuits having voltage levels no greater than 42 V.
Applicable for DL750/DL750P, SL1000 & SL1400

366961 Banana to Alligator 1.2m Cable, 1:1

A subassembly of 1.2 m long test leads with alligator-clip adapters.
Use only for circuits having voltage levels no greater than 42 V.
Applicable for SL1000 & SL1400.

700924 Differential Probe 1400V / 100 MHz

Differential probe powered by Yokogawa Digital Oscilloscopes, ScopeCorders, external power supply or internal battery.

700929 Isolated Passive Probe 1000V / 100 MHz

Passive Probe, 1000Vp CAT II, 100MHz, 10:1, 10MΩ, 1.5m, Isolated Probe, Iso-Probe
Please see also 701947 & accessories.

701901 BNC to Safety Banana 1.8m Cable, 1:1

1000 Vrms-CAT II, 1.8 m long
Safety BNC(male) to safety banana(female) use in combination with 701959, 701954, 758921, 758922 or 758929.

701902/701903 Safety BNC to BNC Cable 1m/2m

701902: 1000 Vtms-CAT II (BNC-BNC), 1 m
701903: 1000 Vrms-CAT II (BNC-BNC), 2 m

701906 Long Test Clip

Set contains one black and one red clip
1000 Vrms-CAT II
2 pieces (red and black) in 1 set 
Connected to the 758933, 758917, or 701901
Length: 0.3m
Applicable for DL750/DL750P, SL1000, SL1400

701926 Differential Probe 7000V / 50 MHz

High Voltage Differential probe powered by Yokogawa Digital Oscilloscopes, ScopeCorders, external power supply or internal battery.

701947 Isolated Probe 1000V / 200 MHz

Passive Probe, 3540Vp-CAT I, 1000Vp-CAT II, 200MHz, 100:1, 100MΩ, 1.5m, 'Isolated Probe'  'Iso-Probe'

720911 External I/O cable

For DL850/E series, PX8000

758917 DMM Measurement Lead Set

A set of 0.8m long red and black test leads, used in combination with a pair of optional 758922 or 758929 alligator-clip adapters.

A1559WL, A1560WL Dedicated Cable

Dedicated Cables for WT1800E /PD option.

A1589WL Direct Current Input Cable

Direct Current Input Cable (with Burden Resistor 2.7 Ohm) for WT1800E /PD2 option.

B9284LK External Sensor Cable

For connection the external input of the WT3000 to the current sensor.
Length: 50cm

366923 BNC to T Adapter

T-adapter for BNC connectors. Use for circuits having voltage levels no greater than 42 V.

701934 External Probe Power Supply

A power supply for current probes, FET probes, and differential probes. Supplies power for up to four probes, including large current probes.

701948 Extension Clip Accessories

Connected to the 700929, 701947
Maximum input voltage: 1,000V (DC + ACpeak)
Length: 0.26m/0.3m/0.4m
Applicable for DL750/DL750P, SL1000, SL1400

701954 Large Alligator Clip (dolphin type)

Set contains one black and one red clip.
1000 Vrms-CAT II.

701963 Soft carrying case for DL850E Series

Three pockets are provided for storing accessories and the user’s manual.

758921 Fork terminal adapter

Adapters for fitting a 4mm banana plug to a fork terminal. Set contains one black and one red clip. 1000 Vrms-CAT II.

758922 Small Alligator-Clip Adapter 300V

Rated at 300 V. Attaches to the 758917 test leads. Sold in pairs.

758923 Spring Hold Safety Terminal Adapter Set

Two adapters in a set (spring-hold type).

758924 BNC to Banana Conversion Adapter

For conversion between BNC and female banana plug
Applicable for DL750/DL750P, SL1000 & SL1400.

758929 Large Alligator Clip Adapter 1000V

Rated at 1000V. Attaches to the 758917 test leads. Sold in pairs.

758931 Screw-Fastened Safety Voltage Terminal Adapter Set

Screw-fastened adapters. Two adapters in a set. 1.5 mm Allen Wrench.

A1323EZ, A1324EZ, A1325EZ Shunt resistor boxes

Shunt resistor boxes for WT1800E /PD option.

A1628WL Direct Current Input Cable

Direct Current Input Cable (without Burden Resistor) for WT1800E /PD2 option

B8213ZA Safety Current Terminal Adapter Set

Two adapters in a set for current input of the PX8000

B9852MJ Power Cable for Differential Probes

The B9852MJ cable supplies power to the 700924, 700925 and 701921 differential probes* from the DL probe power con-nectors. (The probe power option is re-quired on the DL unit.)
* Cable only works with newer 700924, 700925 and 701921 probes that indicate "6VDC or 9VDC"at the probe input power connector. 

B9988AE Printer paper

Quality paper for the DLM2000 /DLM4000 /DL850 /DL6000 /DL9000 and DL750

Overview:

This white paper describes the PZ4000 power analyzer, a discontinued model that has been replaced by the PX8000 Precision Power Scope.

The PZ4000 was developed for power measurement and waveform observation. It features a trend display for the measurement of transient power and a span measurement function. Despite having a wide bandwidth of DC-2 MHz, which facilitates the accurate measurement of switching control waveforms or fluctuating power and a fast sampling rate of 5 MS/s, it is capable of precise measurements at an accuracy of (±0.1% of reading +0.025% of range). It can analyze wide band distorted waveforms with a maximum of 5000 harmonic analysis orders.

Overview:

The Power Analyzer Accuracy and Basic Uncertainty Calculator can be used to determine the uncertainty in voltage, current, and active power (watts) measurement values for various frequency ranges and wiring systems.

Technical Article
Edition 1
Overview:

In power measurement, power analyzer accuracy is one of the most important specifications to consider. It is easy to understand the importance of accuracy but to respect its role in power measurements, one must first understand error.

Accuracy is Error

Error is a measurement’s proximity to the true value, a measurement value accepted as standard. True values vary and can include government-mandated standards or manufacturers’ calibration standards. Accuracy is characterized by the amount of error present in the measurement- its proximity to the true value. The cause of error is either random, with no identifiable root cause, or systematic, introduced by components of the measurement system.

Systematic Errors

Systematic errors can categorized as either gross or measurement. Unknowingly created by a user, gross errors occur as a result of improperly configuring or analyzing the results of a measurement system. Engineers working with a power analyzer could cause a gross error by choosing an inappropriate line filter (see Figure 1). 

Figure 1:

Figure 1

Figure 1: Failing to turn on a required line filter could cause a gross error. In this example, the lack of a filter (top image) results in a signal that is difficult to synchronize

The second type of systematic error, measurement error, is introduced by the power instrument or system itself. Measurement errors can be caused by a lack of calibration, limited instrument accuracy, or measurements that have been altered by the measurement system. A shunt resistor used in a power analyzer will introduce a small measurement error due to the change in voltage it introduces to the system.

Once the error type and source are identified, the next step toward precision is to quantify the accuracy.

Accuracy Quantified

Defined previously, accuracy is the difference between a measured value and a true value. This difference can be expressed as an absolute error - an “error band” surrounding the true value. For example, the absolute error for a voltage measurement might be expressed as:

X [Volts] +/- Y [Volts], where X is the true value and Y is the absolute error.

Figure 2:

Figure 2

Figure 2: Error band surrounding a true value

Absolute error is useful because the total accuracy of a components system is equal to the sum of absolute errors. It is common to express absolute error levels in parts per million (PPM), which specifies the accuracy relative to one million.

1 PPM/V = an error band that is +/- 0.000001V

Relative Error

Power analyzer datasheets typically specify voltage, current, and power accuracies as relatively. Relative errors are simply percentages relative to the measurement and to the full-scale range of the input. For example, the WT3000E Power Analyzer specifies a power accuracy of 0.01% f reading +/- 0.03# of range at 60HZ.

Putting it all Together

Before the total system error can be calculated, it is necessary to convert the power analyzer’s relative error to an absolute error.

Total System Error = Σ(Absolute Errors)

Rather than manually converting relative error to absolute error, an uncertainty calculator can be utilized.

Uncertainty Calculator

Entering the following relative errors into the Uncertainty Calculator yields the corresponding absolute error value.

  • Voltage Reading & Range
  • Current Reading & Range
  • Frequency (kHz)
  • Power Factor (between 0 and 1)

Once entered, the Uncertainty Calculator provides the corresponding accuracies:

  • Voltage Uncertainty (Volts)
  • Current Uncertainty (Amps)
  • Power Uncertainty (Watts / Element)
  • Power Uncertainty for 3-phase, 3-wire configuration (Watts)
  • Power Uncertainty for 3-phase, 4-wire configuration (Watts)

Figures 3 and 4 demonstrate how to use Yokogawa’s Uncertainty Calculator. Remember- simply measuring power does not ensure accuracy or precision. If you struggle with accuracy uncertainty, try an Uncertainty Calculator today.

Figure 3:

Figure 3

Figure 3: Simply entering relative errors in the Yellow cells yields the corresponding absolute error values

Figure 4:

Figure 4

Figure 4 - After entering values in the yellow fields, locate the row that corresponds to the appropriate frequency range to read off the absolute uncertainties for voltage, current and power.

Industries:
Technical Article
Accuracy specifications: Reading it right with range
(Accuracy specifications: Reading it right with range)
Edition 2017
Overview:

The accuracy of a measurement instrument varies with the range over which a reading is measured.

But what if different manufacturers specify this range differently in their instruments?

This article explores the impact of range definitions on measurement accuracy and how one can be mindful when comparing accuracy across instruments.

Overview:

This comprehensive training module covers the following topics:

  • Introduction & Product Familiarization
  • Basic System & Wiring Configurations
  • Basic Setup and Operating Features
  • Step-by-Step Video Demonstrations of Features

Looking for more information on our people, technology and solutions?


Contact Us
Top