WT500 Digital Sampling Power Analyzer / Meter

Mid-Range, up to 3 elements (6 Channels) Basic Power
Wide Current Range: 5mA to 40A , Accuracy: 0.1% of reading


  • Simultaneous measurement of voltage, current, power, and harmonics
  • High-speed data updating (100 ms)
  • Display of numerical values, waveforms and trends
  • Measurement of bought and sold watt hours
  • Easy setup and operation
  • Voltage range: 15 to 1000 V
  • Current range: 0.5 to 40 A
  • Frequency range: DC 0.5 Hz to 100 kHz
  • Basic Power Accuracy: 0.1%
  • Start and Stop recording/logging from an external controller
IIII [+] Options and Applications


  • External sensor input
  • Harmonic Measurement
  • Frequency Measurement
  • Delta Computation
  • GP-IB, Ethernet, VGA output


  • Evaluation and Efficiency Measurements of AC Adaptor, Products with or without Loads
  • Performance Testing of Home Appliances
  • Power Conversion Efficiency and Power Consumption
  • Measuring Fluctuations in Voltage, Current, Power, and Frequency
  • Power Measurements of Green Systems


The WT500 is a sophisticated power Analyzer with fast acquisition rate ideal for analyzing harmonics to the 100th order and transients. The WT500 can display inputs as waveforms, trends and in vector or bargraph format. Versatile integration functions such as active power (WP), current (q), reactive power (WQ), and apparent power (WS), and measurement of bought and sold watt hour. The WT500 can display, analyze and evaluate your power, making it an indispensable tool for Green IT, Energy Star and CO2 reduction.

The WT500 is designed for small current measurement in energy-saving equipment, as well as evaluating currents for large-sized loads. The WT500 works with voltages ranging from 1.5 V up to 1000 V, supporting a wide range of applications. Because it can accept signal inputs for up to six phases, a signal WT500 unit can measure I/O signals on inverters.

IIII [+] Read More

The WT500 also features a color TFT and compact body that enables single-phase and three-phase power measurement, achieving ±0.1% basic accuracy, maximum input of 1000 Vrms, 40 Arms and a wide measurement bandwidth of 100 kHz. The WT500 is an Accepted Device by Standard Performance Evaluation Corporation (SPEC) used for Power Efficiency Benchmarking.

  • Literature
  • Specifications
  • Functions
  • Applications
  • Software
  • Accessories
Literature and Technical Information
pdf icon

Test and Measurement

++ WT500 Power Analyzer | Brochure (1 MB)
++ WT500 Power Analyzer | User’s Manual (21.1 MB)
++ WT500 Power Analyzer | Communication Interface (2 MB)
++ WT500 Power Analyzer | USB Driver (680 kB)
++ WTViewer Software (5.2 MB)
Model: Yokogawa WT500 Power Meter
Model 760201 760203 760203
Number of elements 1 element 2 elements 3 elements
Available with 40A input element
Basic power accuracy: 0.1% of reading +0.1% of range
DC power accuracy 0.1% of reading +0.1% of range
Power frequency range: DC, 0.5 Hz to 100 kHz
V / A frequency range: 100 kHz
Sampling Speed: approximately 100 kS/s
Accuracy range for V / A: 1% to 110%
Inputs Crest Factor: Maximum 300
(for crest factor 3) 15 V, 30 V, 60 V, 100 V, 150 V, 300 V, 600 V, 1000 V
(for crest factor 6) 750m, 1.5, 3, 5, 7.5, 15, 30, 50, 75, 150, 300, 500V
Direct Input: Current
40 A input element  
(for crest factor 3) 500 mA, 1 A, 2 A, 5 A, 10 A, 20 A, 40 A
(for crest factor 6) 250 mA, 500 mA, 1 A, 2.5 A, 5 A, 10 A, 20 A
External Input: Current Sensor
(for crest factor 3) 50 mV, 100 mV, 200 mV, 500 mV, 1 V, 2 V, 5 V, 10 V
(for crest factor 6) 25 mV, 50 mV, 100 mV, 250 mV, 500 mV, 1 V, 2.5 V, 5 V
Data Memory  
Data memory: approximately 20 MB (internal), HDD
Data Update  
Rate: 100 m, 200 m, 500 m, 1, 2, 5 [S]
Measurement Parameters
Main: Voltage, current, active power, reactive power, apparent power, power factor, phase angle, frequency, peak voltage, peak current, crest factor, integration (Wh, Ah, varh, Vah)
  MAX hold
Voltage RMS/MEAN simultaneous measurement
Average active power (user defined function)
Active power integration (WP) (Wh)
Apparent power integration (WS) (VAh)
Reactive power integration (WQ) (varh)
Motor evaluation Power Consumption of Various Motor Loads
Delta Calculation Voltage (V) difference, 3P3W ⇒ 3V3A, ΔY, YΔ
Current (A) difference, 3P3W ⇒3V3A , ΔY, YΔ
Power (W) Δ Y
Harmonic Measurement in Normal Measurement Format PLL synchronization
Frequency PLL source of fundamental frequency : 10 Hz–1.2 kHz.
Window Rectangular
FFT data length 8192
Display: 5.7-inch VGA TFT color LCD, 640 × 480 dots (H × V)
Waveform Display
Numerical: Select 4, 8, 16, Matrix, ALL, Harmonic Single List, Harmonic Dual List, Custom
Bar: Displays the size of each harmonic in a bar graph
Vector: Vector display of phase difference in fundamental waves of voltage and current
Trend display: Number of measurement channels Up to 8 parameters
Displays trends (transitions) in numerical data of the measurement functions in a sequential line graph.
Waveform: Displays the waveforms of voltage, current, torque, speed etc.
Power supply: 100 to 90VAC/264 to 240VAC (automatic switching) — 50/60Hz
Power consumption: Max 80 VA
Operating Temperature: 5 to 40°C, 20 to 80% RH
Dimensions: Approximately 213 (W) x 177 (H) x 409 (D) mm
Weight: Approx. 6.5 kg (main unit with 3 power modules installed)

Simultaneous measurement of DC and AC signals

Evaluation of DC/AC signal conversion technology is critical in the renewable energy market. With input from 2 or more elements, the WT500 can measure DC and AC signals simultaneously and calculate input-to-output efficiency

Separate integration functions for charge/discharge and bought/sold power

The WT500 is equipped with integration functions that can not only evaluate charge and discharge current such as from secondary cells, but also bought and sold power in photovoltaic power generation systems.

WT series for power evaluation of energy-saving equipment

  • Power Evaluation The WT series have been used as power meters for Green IT, Energy Star, CO2 reduction and other energy-saving equipment. The WT500 supports your power evaluation needs.

A Wide Variety of Display Formats

In addition to numerical data, the WT500 can display input signal waveforms and trends
(time variation of numerical data). Also bar graph display and vector display are available with the harmonic measurement (/G5) option.

  • Harmonic
  • Vector
  • Waveform
  • Trend (Capture efficiency changes visually)
  • Display Harmonic Data as Bar Graphs, Vectors, and Lists The harmonic measurements function is a standard feature on the WT500. It is capable of measuring waveforms with a fundamental frequency ranging from 0.5 Hz to 100 kHz , Analysis results up to the 100th order from 50/60 Hz. Fundamental waves can be displayed as numerical values or bar graphs. The WT500 can display harmonic measurement result as lists, and fundamental waves as vectors.

A Variety of integration functions

In addition to integration functions of active power (WP), current (q), reactive power (WQ), and apparent power (WS), a new feature provides measurement of bought and sold watt hours. Also, average active power can be calculated over an integration interval. This feature is useful for evaluating the power consumed by intermittent-control instruments in which the power value fluctuates. Average active power is calculated by using user-defined settings.

  • Active power, current, apparent power, reactive power In addition to the active power integration function (WP) and current integration function (q) included in earlier models, the WT500 also has a new apparent power integration function (WS) and reactive power integration function (WQ).
  • A wide effective input range for high-precision integration The WT500 has a wide effective input range, from 1% to 110% of the measurement range.
  • Average active power (using user-defined settings) Average active power can be calculated over an integration interval. This feature is useful for evaluating the power consumed by intermittent-control instruments in which the power value fluctuates

Delta Calculation

— Harmonic components of up to the 50 th order can be measured with the WT500. You can simultaneously confirm voltage, current, and the distortion factor (THD) as well as measure the distortion factor without switching modes.

  • Checking phase voltage when you measure line voltage
    • Differential voltage/current: Differential voltage and current between two elements are computed in the 3Ø – 3-wire system.
    • Line voltage/phase current: Line voltage and phase current that are not measured are computed in the three-phase 3Ø – 3-wire system
    • YΔ conversion: Line voltage is computed from the phase voltage using the 3Ø – 3-wire system data.
    • ΔY conversion: Phase to neutral is computed from the line voltage in the 3Ø – 3-wire system (3V3A system)

Frequency Measurement (/FQ)

  • Checking the frequencies of all inputs In addition to the standard two channels of frequency measurement, an option is available for frequency measurement on all channels. This option provides frequency measurement of voltage and current on all channels with input elements 1 through 3 installed.
    This is necessary when you want to measure voltage and current frequency from the instrument’s I/O as well as voltage and current frequencies of multiple items under test at the same time. Note: This function cannot be installed on products with only one input element.

Power Measurement for Renewable Energy

  • Measurements of photovoltaic power consumption and power conversion efficiency Photovoltaic power generation systems have been a focus of attention under the backdrop of the prevention of global warming. Thermal power generation and other forms of power based on the limited resources of oil and coal release environmentally harmful CO2, the main cause of global warming. On the other hand, because photovoltaic power generation does not release CO2, it is considered to be an important renewable energy resource for the future. The WT500 is capable of evaluating voltage, current, and power conversion efficiency by measuring DC signals and AC signals generated by photovoltaic power, a renewable energy source

Large Current Measurements for Electrical Appliances

  • Evaluating kitchen appliances such as induction hobs etc. A large amount of current is applied and converted to heat in order to increase the output of IH cooking heaters. The WT500 can measure voltage, current, power, and total harmonic distortion (THD) by inputting the large current (up to 40 A) flowing to the IH cooking heater, without the need for a current sensor. Measurements can be taken faster, allowing for high speed acquisition of power data on manufacturing lines

Evaluation and Testing of Home Electronics

  • Measurement of kitchen appliances such as induction heat hobs etc. Power consumption reduction measures have been adopted in consumer appliances such as air conditioners and washing machines due to implementation of Energy Star. Control methods are used in home electronics in which consumed current is precisely controlled to reduce power consumption. The WT500 provides measurement of the fluctuating power consumption in these appliances

Measuring Power Consumption of Various Motor Loads

  • Industrial motor, pump and air-conditioning fans The revolution speed of these motor & pump has to be controlled in order to save energy, therefore many inverter-driven motor & pump are used. The WT500 not only measures variation of voltage, current and power to evaluate performance of these motor & pump, but also enables you to examine energy efficiency by measuring integrated power

Power Quality Evaluation and Testing of UPS

  • Uninterrupted Power Supplies These systems provide a stable power supply at all times even during power failures such as power outages, instantaneous power failures, voltage fluctuations, and frequency changes. The WT500 can calculate input-to-output efficiency, power output, frequency, and distortion factor of the output waveforms from the UPS

760122 WTViewer Software

WTViewer is a software program that reads measured numerical, waveform, and harmonic data. Data can be transferred to a personal computer via GP-IB, Ethernet, or USB communications to display and store numeric or waveform data. A communications option can be installed in the WT500 as needed.

  • Waveform Display Measured data of input elements 1 to 3, and PΣ can be displayed on the PC screen via communication
  • Waveform Display Voltage and current waveforms can be monitored on the PC screen.
    You can confirm the voltage and current waveform shapes, waveform distortion, and other phenomena

LabVIEW Drivers

Data acquisition possible using LabVIEW. LabVIEW drivers can be downloaded from Yokogawa Web site. (free)

366924 — BNC cable BNC–BNC, 1 m — Qty 1 BNC cable BNC–BNC, 1 meter
366925 —BNC cable BNC–BNC, 2 m — Qty 1 BNC cable BNC–BNC, 2 meters
Adapter Sets, Leads
758917 —Measurement lead — Qty 1 75 cm, two leads (red and black) in a set
758921 —(Fork terminal adapter set) — Qty 1 4 mm fork terminal, banana terminal conversion, red and black (one each)
758922 — Alligator clip adapter (rated for 300 V) — Qty 1 Banana–alligator conversion, two in a set
758923 — Safety terminal adapter — Qty 1 (spring-hold type) Two adapters to a set.
758924— Conversion adapter — Qty 1 BNC-banana-jack(female) adapter
758931 — Safety terminal adapter — Qty 1 (screw-fastened type) Two adapters to a set. 1.5 mm hex Wrench is attached
Conversion Adaptor
751512—Safety-terminal-binding-post adapter— Qty 1 1.5 mm hex Wrench is attached
Current Sensor Units
751521 — Single-phase — Qty 1 DC to 100 kHz (-3 dB). -600 A to 0 A to +600 A (DC), accuracy: (0.05% of rdg* + 40 mA) Superior noise
751522 — Three-phase — Qty 1 DC to 100 kHz (-3 dB). -600 A to 0 A to +600 A (DC), accuracy: (0.05% of rdg* + 40 mA) Superior noise
Clamp-on Probes and Transducers
arrow 751522 — Current transducer — Qty 1 DC to 100 kHz (-3 dB), 600 Apk
arrow 751574 — Clamp- on Probe — Qty 1 30 Hz to 5 kHz, 1400Apk (1000Arms)
arrow 760122 —WTViewer— For WT500 Software
B9316FX — Printer roll pager — Qty 1 Thermal paper, 10 meters (1 roll)
B9284LK —External sensor cable — Qty 1 Current sensor input connector. Length 0.5m
arrow 701960 — Compact Instrument Cart — Qty 1 Compact Cart
arrow 701961 — Deluxe Instrument Cart — Qty 1 Deluxe Cart
arrow 701962 — General-purpose Instrument Cart — Qty 1 General-purpose Cart
arrow 7511533-E4 — Rack Mount Kit — Qty 1 For EIA
arrow 7511534-E4 — Dual Rack Mount Kit — Qty 1 For EIA