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

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. 

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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.

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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.


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


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

  • 366924 BNC to BNC cable for oscilloscope 
  • 1m BNC wire
  • Simultaneous measurement with 2 units
  • Input external trigger signal

700924 Differential Probe 1400V / 100 MHz

  • Differential oscilloscope probe
  • 100 MHz
  • ±1400 V (DC + ACpeak) at 1000:1
  • Power: Internal battery or probe power supply
  • Works with Oscilloscopes, ScopeCorders

366925 BNC to BNC 2m Cable

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

700929 Isolated Passive Probe 1000V / 100 MHz

  • Versatile 700929 passive oscilloscope probe
  • 100MHz frequency bandwidth
  • Isolated input module of ScopeCorder series
  • For use with isolated BNC inputs

366926 BNC to Alligator 1m Cable, 1:1

  • 1 m long BNC to alligator clip cable
  • Only for circuits with voltage levels no greater than 42 V
  • Applicable for DL750/DL750P, SL1000 & SL1400

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

  • 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)
  • 701959, 701954, 758921, 758922, 758929

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.

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

  • 701902/701903 Safety BNC to BNC Cable for oscilloscope
  • Safe, high-voltage measurements with DL350, DL950, and SL1000 isolated input modules 
  • 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

50 MHz, 1000:1/100:1, Max. Differential Voltage: 5000 Vrms/7000 Vpeak (1000:1), Probe Power: Internal battery or probe power supply B9852MJ power cable is bundled Work with Oscilloscopes, ScopeCorders

701947 Isolated Probe 1000V / 200 MHz

  • 1.5m Isolated Probe (ScopeCorder)
  • DC to 200 MHz bandwidth 
  • 100:1 attenuation Isolated
  • BNC connector type 
  • For ScopeCorder Isolated Modules

720911 External I/O cable

For DL850/E series, PX8000

758917 DMM Measurement Lead Set

  • Set of 0.8m long red and black multimeter test leads
  • Used in combination with a pair of optional 758922 or 758929 alligator-clip adapters
  • 1000 Vrms, 32 Arms CAT II

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

  • 701934 External Probe Power Supply
  • 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.

A1559WL, A1560WL Dedicated Cable

Dedicated Cables for WT1800E /PD option.

758921 Fork terminal adapter

  • 758921 Fork Terminal Adapters
  • For fitting a 4mm banana plug to a fork terminal
  • 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.

A1589WL Direct Current Input Cable

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

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

  • Yokogawa 758929 Alligator Clip Adapter 
  • Rated at 1000V
  • Attaches to 758917 test leads
  • Sold in pairs black/red

758931 Screw-Fastened Safety Voltage Terminal Adapter Set

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

B9988AE Printer paper

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

B8213ZA Safety Current Terminal Adapter Set

Two adapters in a set for current input of the PX8000

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

CT60/ CT200/ CT1000/ CT1000A/ CT2000A AC/DC Current Sensor

AC/DC current sensors capable of highly accurate measurement starting in DC range.

AC/DC Split Core Current Sensor CT1000S

Measure high currents without disassembling existing cabling. Compatible with power analyzers and waveform measurement instruments.

  • Power Analyzer Accuracy and Basic Uncertainty Calculator from Yokogawa Test&Measurement 
  • Determine uncertainty in voltage, current, and active power (watts) measurement values
  • Various frequency ranges and wiring systems
Technical Article
Accuracy specifications: Reading it right with range  
(Accuracy specifications: Reading it right with range)
Edition 2017

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.

Download the article now

10 + 1 Reasons why you aren’t measuring power accurately  
(10 + 1 Reasons why you aren’t measuring power accurately)
Edition 2017

Are you achieving the levels of accuracy you need? 

This article outlines the top reasons for inaccuracies in power measurements and how to tackle them.

Download the article to learn about:   

  • Validity of instrument specifications
  • External sensors and temperature effects
  • Calibrating a measurement set up

Download the article now

Technical Article
Choosing the power measurement solution that is right for you  
(Choosing the power measurement solution that is right for you)
Edition 2017
Infographic: Getting started with electrical power measurements  
(Infographic: Getting started with electrical power measurements)
Edition 2017

Energy efficiency directives from bodies like International Electro technical Commission (IEC), European commission, California Energy Commission (CEC) and others govern standards across various classes of electrical, electronic and mechatronic equipment.

This infographic provides a snapshot guide for making reliable power measurements across your product development lifecycle with particular emphasis on the high accuracy needs of compliance testing. 

Technical Article
Yokogawa VIP Suite for Power Measurements  
(Yokogawa VIP Suite for Power Measurements)
Edition 2018
T&M Magazine ed. 4 (Jan 2016)
(T&M Magazine ed. 4 (Jan 2016))
Edition 012016
T&M magazine no 2
(T&M magazine no 2 (May 2014))
Edition 05.2014
T&M Magazine no 3
(T&M Magazine no 3 (Feb 2015))
Edition 02.2015

Product Overviews



    This video demonstrates how to measure transient phenomena on power signals using the Yokogawa Test&Measurement PX8000 Precision Power Scope.

    In several applications, especially those testing AC power to a standard such as IEC61000-3-11, the voltage and current signals must be monitored to confirm there are no major dips and/or swells in the signal. This can be done with instruments capable of reporting rms values, including power analyzers, traditional oscilloscopes, and some data acquisition systems.

    To test to a standard, however, the instrument must have an accuracy spec that is traceable back to a national standard of calibration such as ISO17025 or NIST.



    Although DC power measurements can be fairly straightforward, complexities with AC power measurements arise when dealing with distorted waveforms, fluctuating power factors, and multiple phases, which introduce intricacies that complicate an otherwise simple measurement process.

    This on-demand webinar provides an informative dive into the various fundamental aspects of power measurement and includes:

    • A look at multi-phase measurements and measurement techniques
    • A review of practical applications
    • Real-world examples

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