Yokogawa WT333 Data Sheet

Digital Power Meter

WT

DIGITAL POWER METER

300 Series

THE 5TH GENERATION OF THE WORLD'S
BEST SELLING POWER METER

High Performance and Reliability

 Basic Accuracy of 0.1% of Reading

 Low Current Measurement down to 50 micro-Amps

 DC, 0.5 Hz to 100 kHz Frequency Range

 Standard USB, and GPIB or RS232 Interfaces

Bulletin WT300-01EN

Yokogawa’s new compact WT300 series for reliable power measurement

The WT300 series is the 5th generation of
Yokogawa’s compact power meter portfolio.
The world’ s best selling power meter is the
power meter of choice in multiple industries
from production lines to R&D applications.

WT310HC(1ch, MAX40A) WT332(2ch)/WT333(3ch)WT310(1ch)

Wide current input range with high performance and reliability PC, Data Logger and External Sensors connectivity

Key Features Applications Software & Tool Specification

Wide current input ranges

The WT300 series offers customers a wide range of current inputs from a
few mA right up to 40Arms.
It can measure both AC and DC.

Current range by model

WT332 WT333

WT310

WT310HC

50uA

5mA 10mA 20A 26A 40A

Ranges

15.000 to 600.00V

0.5000A to 20.000A

5.0000mA to 20.000A

1.0000A to 40.000A

DC to 100kHz, 20A

DC to 100kHz, 20A

DC to 20kHz, 40A

Fast display and data update rate

The fast display and 100ms maximum data update rate of the WT300 series
offers customers a short tact time in their testing procedures.
Consistent Basic Measurement Accuracy for all input ranges.

0.1% of reading + 0.1% of range (50Hz/60Hz)

Simultaneous measurement of all parameters

A WT300 series can measure all DC and AC parameters. It can also measure
harmonics and perform integration simultaneously without changing the
measurement mode. The WTViewerFreePlus software is used to monitor and
save all these parameters.

Example of WTViewerFreePlus display

Convenient measurement functions

- MAX hold function

The maximum values of RMS/PEAK voltage & current active power, reactive

power and apparent power can be held.

- Line filter and frequency filter capability

These filter functions will cut off unnecessary noise & harmonic

components for fundamental waveform measurements.

The WT300 series offers a wide range of communication interfaces such as USB, GP-IB or RS-232 (Selectable) and
Ethernet (Optional).

Customers therefore have the flexibility to choose
according to their application needs e.g. from
production lines to engineering test benches.
Customers can use WTViewerFreePlus software to
set up all kinds of measurements. Additionally, the
numeric values, waveform display* and trend
graphs of the measurement data can be displayed
and saved.

* Waveform display requires the /G5 Harmonic option

D/A output for measurement recording

The D/A option is used to output Voltage,
Current, Power and other measured data
for recording to data loggers (+/-5Vdc
outputs).
(WT310/WT310HC 4CH, WT332/WT333
12CH)

Test bench Air conditioner evaluation Production line test system

Current sensor input

Customers have the option to
select either 2.5V to 10V
range (/EX1 option) or 50mV
to 2V range (/EX2 option)
inputs for measuring large
currents using current
clamps or current sensors
with voltage outputs.

Motor’s Megawatts

External input for current
sensor

First in Class* and First in Industry*

First in class : Auto ranging function available in selected ranges

The auto-range function is used to select/change the range automatically in specific ranges.
This results in shorter range changing times and thus quicker and more efficient testing.

Image of Range skip (configuration) function operation

02

Input signal changes

Action of Yokogawa’s previous model

Range

Change available ranges stepwise

Action of WT310/WT330 series

Range change ends

* According to YOKOGAWA survey by Dec, 2012

change ends

Change to selected
next range

First in industry : Integration measurement auto ranging function

Conventionally, when power meters operate in an integration mode to measure power consumption and standby power, the measuring ranges need to be fixed.
However, if the level of the input exceeds the maximum of the selected range, the results will be incorrect and the test will need to be repeated with higher ranges
applied.
The WT300 series has a high speed automatic ranging capability in integration mode which removes this need to repeat the test and integration is continuous and
accurate.
This function is not only available for +/- Wh but also for Ah and DC current.

03

WT300 power meters are easy to use, cost effective and accurate for
a wide range of applications in Production, Testing, Evaluation and R&D.

For Home appliances and Office equipment For Industrial equipment and Transportation

Production line or QA testing of
electric Devices

- Compact half rack mount size helps customers build smaller
test systems with a better Return on Investment (ROI).

- D/A output function for data recording

- Multiple communication interfaces. USB, RS-232 or GP-IB and
Ethernet capability.

The simultaneous measurement of power consumption parameters such as
U, I, P, frequency, Power Factor and Harmonics for production line or QA
testing results in reduced tact times. Thus testing is faster and cheaper. The
DA output and communication interfaces enable data to be remotely and
flexibly captured.

system

Development and evaluation tool for
home appliances

- 5mA range helps small current measurement (WT310)

- Auto ranging function under Integration mode

- Range skip (range configuration) function provides the ability
to select the usable ranges in advance. Auto ranging enables
the WT300 series to rapidly adapt to changing input
conditions.

The range skip function reduces the range change transition period. The
WT310 can measure both large and small currents accurately in a single test.
This can reduce the total evaluation period or removes the need to use two
rather than one power meters for the application, thereby saving capital cost.

Image of
range configuration function
for WT300 series

Input signal changes

* Comparison with Yokogawa’s previous model WT210/WT230

Action of Yokogawa’ s previous model*

Range

Change available ranges stepwise

Action of WT310/WT330 series range configration

Range change ends

change ends

Change to selected
next range

Automotive - Battery or DC driven
device evaluation

- Accurate DC measurement: 0.3% total (WT310HC: 0.5% total)

- Direct high current measurement up to 40A without any
external current sensor (WT310HC).

- Charge/Discharge (+/-Wh, +/-Ah) energy measurement for
batteries

The WT310HC can measure currents up to 40A directly.
This provides a cost effective and accurate method for testing DC driven
devices in vehicles without having to use extra sensors.

Navigation device

Audio Visual device for vehicle

Duration testing and efficiency
measurement for industrial motors
and rotating machinery

- Integration measurement for long period

- D/A output function for data recording

- DC, 0.5Hz to 100kHz broad bandwidth capability

The WT300 series provides reliable current integration (Ah) and Energy (Wh)
measurement for up to 10,000 hours (approx. 1 year). The D/A option is used
to save and monitor the measurement results (WT310/WT310HC: 4ch,
WT332/WT333: 12ch). An external recorder or data logger like, a ScopeCorder,
can be used to save this D/A function data along with other parameters such
as temperatures, torque and rotation speed.

Voltage

Motor’s Megawatts

Key Features Applications Software & Tool Specification

External input for
current sensor

Testing to international standards,
such as IEC62301,
Energy Star and SPECpower

- The WT310 has a high measurement resolution of Max.
100µW under the 5mA range setting.

- Simultaneous measurement of normal power parameters,
harmonic components and THD.

- Dynamic input capability of crest factor Max 300 (Peak value
/ minimum effective RMS value)

- Free PCM software for IEC62301 testing

The WT310 together with the power consumption measurement (PCM)
software enables users to perform standby power testing according to
international standard.

WTViewerFreePlus
PCM software

DUT

Evaluation of large current equipment
such as Induction Heaters/Cookers

- Direct high current measurement up to 40Arms without using
external current sensors (WT310HC).

- Auto ranging function for Integration mode

The WT310HC allows 40Arms to be directly inputted without the requirement to
use current clamps or current sensors. This not only provides more precise
measurement but also saves on investment costs. The wide current ranges are
from 1A to 40A and voltage ranges are from 15 V to 600 V.
Customers can use it for the evaluation of special waveform driven devices
such as IH cookers and heaters.

Single Phase voltage

IH Cooking Heater

Evaluation testing of special waveform
driven devices and distorted
waveforms (including DC component)

- DC, 0.5Hz to 100kHz broad bandwidth capability

- Average active power measurement under integration mode

The WT300 series has a broad frequency capability of DC and from 0.5Hz to
100kHz. It can measure the RMS value of distorted waveforms like square
waveforms or special waveform driven devices. The average active power
measurement function gives accurate power consumption data for fluctuating
power devices such as burst waveform operated devices. Therefore the
customer can perform accurate distorted waveform measurements without
using special mode settings.

UI

tt

Burst Waveform Square Waveform

Conformance and evaluation testing
of uninterruptable power supplies
(UPS)

- Maximum order setting for THD calculations

- Efficiency measurements using a single power meter

- Average active power measurement under integration Mode

The WT300 series enables users to conduct conformity tests according to UPS
performance testing standards. The WT300 series is used to measure and
calculate input & output levels, the efficiency, frequency and THD. The average
active power data also provides accurate values of power consumption. The
WT300 series along with the WTViewerFreePlus software helps to
simultaneously measure all the necessary parameters required to test a UPS
thereby reducing the evaluation time.

UPS

WTViewerFreePlus : PC Software

Please visit the URL below which shows many applications and examples. It will be regularly updated with the latest applications.

04

http://tmi.yokogawa.com/technical-library/application-notes/

05

Easy set up and display of Numeric data,

Trend graphs and Waveforms using PC application software

WTViewerFreePlus For WT300 Series (included) LabVIEW Drivers Programming tool samples

Support tools for creating dedicated programs!

The WTViewerFreePlus software can capture measured numeric values, harmonic values and waveform data. The data can be
transferred to a PC via a USB, GP-IB/RS-232 or Ethernet communication interface, and it can be displayed* and saved on the
PC.

* Waveform display requires /G5 Harmonic option.

Setting Window Measurement Window

As well as using the WT300 series front panel to setup the powermeter,
you can use the software to quickly set up your favorite conditions.
It also shows all the setting parameters and the status at a glance. In
particular, you can set up the range-skip function (range -configuration
setting) and specify the maximum order used for the THD calculation.

The software can display items which cannot be shown on the display
of the WT300 series, such as multiple numeric measurement
parameters, the harmonics data of each order, bar graphs, trend graphs
and voltage & current waveforms. The free software thus adds
additional performance to the WT300 series.

* Please check the Instruction manual in the CD for more information.

Standby power measurement conforming to IEC62301 Ed2.0

Power Consumption Measurement Software (Free)

The Power Consumption Measurement Software together with a WT310 (or another WT series instrument) provides a
trustworthy power measurement solutions for testing the standby and off mode power of household products and office
equipment.
The solution enables testing to be performed according to the IEC62301 Ed1.0 and Ed2.0 standards which specify the use of
special algorithms for determining the power stability in the device under test. The software thus gathers all the required
measurement data from the WT310, which includes not only voltage/ current/ power/ frequency but also the total harmonic
distortion (THD) and the crest factor (CF) of the AC power supply. We therefore also recommend that the WT310 is installed
with the harmonic option (/G5) and that a low distortion power supply is used for the test.

Data acquisition is
possible using
LabVIEW. LabVIEW
drivers can be
downloaded from

To help you create dedicated programs for your system, we
provide sample programs which support Visual Basic/Visual
C++/Visual Basic .NET and Visual C# *. The sample programs
support communication via USB, GP-IB/RS-232 or Ethernet

interfaces and can be downloaded from our Web site.
our Web site.
(Free of charge)

Coming soon

* LabVIEW is a registered trademark of NATIONAL INSTRUMENTS Corporation in the U.S.A.

* Visual Basic, Visual C++, Visual Basic .NET and Visual C# are registered trademarks
of MICROSOFT Corporation in the U.S.A.

Comparison between WT210/230 series and WT310/330 series

WT310/WT332/WT333

DC power measurement accracy

Current range
(Crest factor=3)

Effective input range for voltage & currnet (CF=3)
Maximum displaying value for voltage & current (CF=3)

Simultaneous measurement of RMS, VotageMEAN & DC
Frequecy measurement
Number of display item
Sampling rate
Harmoinc measurement
THD calculation maximum order setting
Auto ranging of integaration

Communication interface

IEEE stanndard for GP-IB
Comparetor function
Viewer software (setting & data capturing)

*1: Simultaneous, mode independent measurement using the WTViewerFreePlus PC software.
*A command compatible mode for the previous WT200 series is prepared. (IEEE488.2 only)
In that mode, the WT300 series works identically to a WT200 series except for the Store (and recall operation) and the Compare functions.

Direct input

External current input

0<PF<1

USB
GP-IB
RS-232
Ethernet

0.1% of reading+0.2% of range
5m/10m/20m/50m/100m/200m/

0.5/1/2/5 /10/20[A] (WT310)

0.5/1/2/5/10/20[A] (WT332/WT333)
EX1: 2.5//5/10[V]

EX2: 50m/100m/200m/500m/1/2[V] (OP.)

1% to 130%
1% to 140%

Power reading x {power reading error +

(power range / apparent power reading) +

tanØ x (influence when PF = 0)} %

2 channels (voltage and current)

1

Yes *

4 items

Approximately 100 kS/s

Yes (OP, / G5)

Yes (OP, 1-50th)

Yes

Yes
Yes GP-IB or RS-232
Yes GP-IB or RS-232

Yes (OP)

IEEE488.2

No

Free (included)

EX2: 50m/100m/200m/500m/1/2[V] (OP.)

(power range / apparent power reading) +

WT310HC

0.3% of reading+0.2% of range

1/2/5/10/20/40[A]

EX1: 2.5//5/10[V]

1% to 100% (40A range only)
1% to 110% (40A range only)

Power reading x {power reading error +

tanØ x (influence when PF = 0)} %

2 channels (voltage and current)

1

Yes *

4 items

Approximately 100 kS/s

Yes (OP, / G5)

Yes (OP, 1-50th)

Yes

Yes
Yes GP-IB or RS-232
Yes GP-IB or RS-232

Yes (OP)

IEEE488.2

No

Free (included)

WT210/WT230

0.3% of reading+0.2% of range

5m/10m/20m/50m/100m/200m/

0.5/1/2/5 /10/20[A] (WT210)

0.5/1/2/5/10/20[A] (WT230)
EX1: 2.5/5/10[V]

EX2: 50m/100m/200m[V] (OP.)

1% to 130%

1% to140%

Add the power reading x

{tanØ x (influence when PF = 0)}%.

No

selected voltage or current (one)

3 items

Approximately 50 kS/s

Yes (OP, / HRM)

No
No

No
Yes (OP) GP-IB or RS-232C
Yes (OP) GP-IB or RS-232C

No

IEEE488.1 and IEEE488.2

Yes

Free (download)

Superior points
Changed points

Key Features Applications Software & Tool Specification

Rear View

6

1

2

Configuring and Establishing a New Connection between the WT310
and a PC

Test Report

Voltage input terminals

1

Current Input terminals

2

External current sensor input

3

USB communication interface

4

GP-IB/RS-232 (Standard)

5

Ethernet (Optional)

6

D/A output connector

7

3

1

5

4

3

2

7

6

06

5

7

4

07

Example of basic characteristics Specification

Example of Frequency -power Accuracy Characteristics

Error [% of range]

- 10%

10%

5%

0%

- 5%

WT310 150V/1A range

WT310_Spec and reference values_Upper

WT310_Spec and reference value_Lower

WT310HC 150V/10A range

WT310HC_Spec and reference values_Upper

WT310HC_Spec and reference values_Lower

10 100 1,000 10,000 100,000

Frequency [Hz]

Example of frequency versus power accuracy characteristic

10%

WT310 150V/1A range

WT310HC 150V/10A range

5%

0%

Spec and reference values_Upper

Spec and reference values_Lower

(power specification for cosØ=0)

Error [% of VA]

- 5%

- 10%
10 100 1,000 10,000 100,000

Frequency [Hz]

Exterior View

179

250
213

73 23

88

19

359
356

WT310 series WT330 series

Unit : mm Unit : mm

Specification

Input
Item Specifications
Input terminal type Voltage
Plug-in terminal (safety terminal))
Current

• Direct input: Large binding post

• External current sensor input option: isolated BNC connector

Input format Voltage
Floating input through resistive voltage divider
Current
Floating input through shunt
Measurement range Voltage

Crest factor 3: 15V/30V/60V/150V/300V/600V
Crest factor 6: 7.5V/15V/30V/75V/150V/300V

Current

• Direct input:
Crest factor 3:

• WT310: 5mA/10mA/20mA/50mA/100mA/200mA/0.5A/1A/2A/5A/10A/20A

• WT310HC: 1A/2A/5A/10A/20A/40A

• WT332 and WT333: 0.5A/1A/2A/5A/10A/20A
Crest factor 6:

• WT310: 2.5mA/5mA/10mA/25mA/50mA/100mA/0.25A/0.5A/1A/2.5A/5A/10A

• WT310HC: 0.5A/1A/2.5A/5A/10A/20A

• WT332 and WT333: 0.25A/0.5A/1A/2.5A/5A/10A

• External current sensor input (/EX1,/EX2):

Total power Error with rated range input for an arbirtary power factor

1.00%

0.10%

(f=50/60Hz)

Error [% of range]

0.01%

0.001 0.010 0.100 1.000

Power Factor

Effect of common mode voltage on reading value

(Common Voltage 600Vrms)

Error [% of range]

5%

4%

3%

2%

1%

0%

WT310 15V range

WT310 0.5A range

Spec and reference values

10 100 1,000 10,000 100,000

Frequency [Hz]

* Performance of WT332/WT333 is same as that of WT310

13

213

23

327

34

28.5

132

20

Crest factor 3:

• EX1: 2.5V/5V/10V or EX2: 50mV/100mV/200mV/500mV/1V/2V
Crest factor 6:

• EX1: 1.25V/2.5V/5V or EX2: 25mV/50mV/100mV/250mV/500mV/1V

Input impedance Voltage

Input resistance: Approx. 2 MΩ, input capacitance: Approx. 13 pF in parallel

with the resistance
Current

• Direct input

• WT310
Crest factor 3: 5mA/10mA/20mA/50mA/100mA/200mA
Crest factor 6: 2.5mA/5mA/10mA/25mA/50mA/100mA
at the above range setting,
Input resistance: Approx. 500mΩ,
Input inductance: Approx. 0.1uH in series with the resistance
Crest factor 3: 0.5A/1A/2A/5A/10A/20A
Crest factor 6: 0.25A/0.5A/1A/2.5A/5A/10A
at the above range setting,
Input resistance: Approx. 6 mΩ + 10 mΩ (max)*Factory setting
Input inductance: Approx. 0.1uH in series with the resistance

• WT310HC
Crest factor 3: 1A/2A/5A/10A/20A/40A
Crest factor 6: 0.5A/1A/2.5A/5A/10A/20A
Input resistance: Approx. 5mΩ,input inductance: Approx. 0.1uH in series

with the resistance

• WT332/WT333
Crest factor 3: 0.5A/1A/2A/5A/10A/20A
Crest factor 6: 0.25A/0.5A/1A/2.5A/5A/10A
Input resistance: Approx. 6mΩ, input inductance: Approx. 0.1uH in series

with the resistance

• External current sensor input (/EX1):
Crest factor 3: 2.5V/5V/10V
Crest factor 6: 1.25V/2.5V/5V
Input resistance: Approx. 100k

• External current sensor input (/EX2):
Crest factor 3: 50mV/100mV/200mV/500mV/1V/2V
Crest factor 6: 25mV/50mV/100mV/250mV/500mV/ 1V
Input resistance: Approx. 20k
Instantaneous maximum Voltage
allowable input Peak value of 2.8 kV or RMS value of 2.0 kV, whichever is less.

(1 period, for 20 ms) Current

• Direct input

• WT310
Crest factor 3: 5mA/10mA/20mA/50mA/100mA/200mA
Crest factor 6: 2.5mA/5mA/10mA/25mA/50mA/100mA
at the above range setting,
Peak value of 150A or RMS value of 100 A, whichever is less.
Crest factor 3: 0.5A/1A/2A/5A/10A/20A
Crest factor 6: 0.25A/0.5A/1A/2.5A/5A/10A
at the above range setting,
Peak value of 450A or RMS value of 300 A, whichever is less.

• WT310HC
Crest factor 3: 1A/2A/5A/10A/20A/40A
Crest factor 6: 0.5A/1A/2.5A/5A/10A/20A
Peak value of 450A or RMS value of 300 A, whichever is less.

• External current sensor input
Peak value less than or equal to 10 times of the rated range.

• WT332/WT333
Crest factor 3: 0.5A/1A/2A/5A/10A/20A
Crest factor 6: 0.25A/0.5A/1A/2.5A/5A/10A
Peak value of 450A or RMS value of 300 A, whichever is less.
Instantaneous maximum Voltage
allowable input Peak value of 2kV or RMS value of 1.5kV, whichever is less

(for 1 s) Current

• Direct input

• WT310
Crest factor 3: 5mA/10mA/20mA/50mA/100mA/200mA
Crest factor 6: 2.5mA/5mA/10mA/25mA/50mA/100mA
at the above range setting,
Peak value of 30A or RMS value of 20A, whichever is less.
Crest factor 3: 0.5A/1A/2A/5A/10A/20A
Crest factor 6: 0.25A/0.5A/1A/2.5A/5A/10A
at the above range setting,
Peak value of 150A or RMS value of 40A, whichever is less.

• WT310HC
Crest factor 3: 1A/2A/5A/10A/20A/40A
Crest factor 6: 0.5A/1A/2.5A/5A/10A/20A
Peak value of 150A or RMS value of 44A, whichever is less.

• WT332/WT333
Crest factor 3: 0.5A/1A/2A/5A/10A/20A
Crest factor 6: 0.25A/0.5A/1A/2.5A/5A/10A
Peak value of 150A or RMS value of 40A, whichever is less.

• External current sensor input
Peak value less than or equal to 10 times of the rated range.
Continuous maximum Voltage
allowable input Peak value of 1.5kV or RMS value of 1kV, whichever is less.

Current

• Direct input

• WT310
Crest factor 3: 0.5A/1A/2A/5A/10A/20A
Crest factor 6: 0.25A/0.5A/1A/2.5A/5A/10A
at the above range setting,
Peak value of 100A or RMS value of 30A, whichever is less.
Crest factor 3: 5mA/10mA/20mA/50mA/100mA/200mA
Crest factor 6: 2.5mA/5mA/10mA/25mA/50mA/100mA
at the above range setting,
Peak value of 30A or RMS value of 20A, whichever is less.

• WT310HC
Crest factor 3: 1A/2A/5A/10A/20A/40A
Crest factor 6: 0.5A/1A/2.5A/5A/10A/20A
Peak value of 100A or RMS value of 44A, whichever is less.

• WT332/WT333
Crest factor 3: 0.5A/1A/2A/5A/10A/20A
Crest factor 6: 0.25A/0.5A/1A/2.5A/5A/10A
Peak value of 100A or RMS value of 30A, whichever is less.

• External current sensor input
Peak value less than or equal to 5 times of the rated range.
Continuous maximum Common- mode voltage (during 50/60 Hz input)
600Vrms CAT II
Influence of common When 600 Vrms is applied between the input terminal and with the voltage input
mode voltage terminals shorted, current input terminals open and external current sensor input

terminals shorted.

Double the following values when the crest factor is set to 6.

• At 50/60 Hz
–80 dB or more (±0.01% of range or less)

• Up to 100 kHz (reference value)

0.01% of range or more. f is frequency of input signal in kHz.

• 15 V, 30 V, 60 V, 150 V, 300 V, 600 V ranges, 0.5 A, 1 A, 2 A, 5 A, 10 A, 20 A

ranges of WT310/WT332/WT333, 1 A, 2 A, 5 A, 10 A, 20 A, 40A ranges of

WT310HC and, external current sensor input (/EX2 Option)

(Rated range)
The maximum rated range is 600 V for the voltage input terminal and 20 A for the

current input of WT310/WT332/WT333 and 40 A for the current input terminal of

WT310HC and 2 V for option /EX2.

• 5mA, 10mA, 20mA, 50mA, 100mA and 200mA range of WT310

(Rated range)
The Maximum rated range is 20A.

• External current sensor input (/EX1 Option) ranges

(Rated range)
The maximum rated range is 10 V
Line filter Select OFF or ON (cutoff frequency of 500 Hz).
Frequency filter Select OFF or ON (cutoff frequency of 500 Hz).
A/D converter Simultaneous conversion of voltage and current inputs.
Resolution: 16 bits.
Maximum conversion rate: Approx. 10us.

Within ±

Within ±

Within ±

(Maxmum rated range)

{

(Maxmum rated range)

{

(Maxmum rated range)

{

Ω

Ω

× 0.001 × f% of range

× 0.0002 × f% of range

× 0.01 × f% of range

}

}

}

Voltage and Current Accuracy
Item Specifications

Accuracy Requirements
Temperature: 23±5°C, Humidity: 30 to 75%RH.,
Input waveform: Sine wave, Crest factor: 3, Common-mode voltage: 0 V
Scaling function: OFF, Number of displayed digits: 5 digits
Frequency filter: Turn ON to measure voltage or current of 200 Hz or less

After warm-up time has passed

After zero-level compensation or measurement range is changed.

Accuracy (at 12 months)

(The accuracy shown below is the sum of reading and range errors.)
* f in the read error equation is the input signal frequency in kHz.

WT310,WT330 WT310HC WT310HC

(Voltage/Current) (Voltage, Current EXT (Current Direct input)

sensor input)

DC ±(0.1% of reading ±(0.1% of reading ±(0.2% of reading

+0.2% of range) +0.2% of range) +0.2% of range)

≤

0.5Hz

f < 45Hz ±(0.1% of reading ±(0.1% of reading ±(0.1% of reading

+0.2% of range) +0.2% of range) +0.2% of range)

≤ f ≤

45Hz

66Hz ±(0.1% of reading ±(0.1% of reading ±(0.1% of reading

+0.1 % of range) +0.1 % of range) +0.1 % of range)

≤

66Hz < f

1kHz ±(0.1% of reading ±(0.1% of reading ±(0.1% of reading

+0.2 % of range) +0.2 % of range) +0.2 % of range)

≤

1kHz < f

10kHz ±{(0.07×f)% of reading ±{(0.07×f)% of reading ±((0.13*f)% of reading

+0.3 % of range} +0.3 % of range} +0.3 % of range)

≤

10kHz < f

20kHz ±((0.13*f)% of reading

+0.5 % of range)

±(0.5 % of reading ±(0.5 % of reading

≤

10kHz < f

100kHz +0.5 % of range) +0.5 % of range)

±[{0.04×(f–10)}% of reading ±[{0.04×(f–10)}% of reading

• Influence of temperature changes after zero-level compensation or range change
Add 0.02% of range/°C�to the DC voltage accuracy. Add the following value to the DC current accuracies.
WT310 (5mA/10mA/20mA/50mA/100mA/200mA ranges): 5uA/°C�
WT310 (0.5A/1A/2A/5A/10A/20A ranges) and WT330 direct current input: 500uA/°C
WT310HC direct current input: 1mA/°C�
External current sensor input (/EX1): 1mV/°C�
External current sensor input (/EX2): 50uV/°C�

• Accuracy of the waveform display data, Upk and Ipk
Add the following value to the above accuracy (reference value). The effective input range is within ±300% of

range (within ±600% for crest factor 6)
Voltage input: 1.5 ��(15/range) % of range
Direct current input range:
WT310�(5mA/10mA/20mA/50mA/100mA/200mA range): 3 ��(0.005/range) % of range
WT310�(0.5A/1A/2A/5A/10A/20A range) and WT330 direct current input: 3 ��(0.5/range) % of range
WT310HC direct current input: 3 ��(1/range) % of range
External current sensor input range:
/EX1 Option: 3 ��(2.5/range) % of range
/EX2 Option: 3 ��(0.05/range) % of range

• Influence of self-generated heat caused by voltage input

Add 0.0000001 ×U2% of reading to the AC voltage accuracies.
Add 0.0000001 ×U2% of reading + 0.0000001 ×U2% of range to the DC current accuracies. U is the
voltage reading (V).

Influence of self-generated hea t caused by voltage input lasts until falling the temperature of the input resistor

even if voltage input decreases.

• Influence of self-generated heat caused by current input
WT310:

Add 0.00013 × I2% of reading to the AC current accuracies.
Add 0.00013 × I2% of reading + 0.004 × I2 mA (0.5A/1A/2A/5A/10A/20A range) or 0.00013 × I2% of
reading + 0.00004 × I2 mA (5mA/10mA/20mA/50mA/100mA/200mA range), to the DC current accuracies.
I is the current reading (A).

WT310HC:
Add 0.00006 × I2% of reading to the AC current accuracies.
Add 0.00006 × I2% of reading + 0.001 × I2 mA to the DC current accuracies. I is the current reading (A).
WT332/WT333:

Add 0.00013 × I2% of reading to the AC current accuracies.
Add 0.00013 × I2% of reading + 0.002 × I2 mA to the DC current accuracies. I is the current reading (A).

Influence of self-generated hea t caused by current input lasts until falling the temperature of the shunt resistor

even if current input decreases.

• Accuracy changes caused by data update interval
When the data update interval is 100 ms, add 0.05% of reading to the 0.5Hz to 1kHz accuracy.

• Guaranteed accuracy ranges for frequency, voltage, and current
All accuracy figures for 0.5 to 10 Hz are reference values
The current accuracy figures for DC, 10 Hz to 45 Hz, and 400 Hz to 100 kHz when the current exceeds 20 A are

reference values.
Input range 1 to 130% with respect to the rated range of voltage or current. (It displays up to140%)

* WT310HC: 40ARange Only 1 to 100%(display is 110%)
(Add the reading error × 0.5 to above accuracies for the range of 110% to 130% of the

rated range.)

Measurement data update interval Measurement Frequency Range
frequency range 0.1s DC, 25Hz

0.25s DC, 10Hz

0.5s DC, 5Hz
1s DC, 2.5Hz
2s DC, 1.5Hz
5s DC, 0.5Hz
Only for direct current input of WT310HC, the maximum measurement range is 20kHz.
When the line filter is 45 to 66 Hz: Add 0.2% of reading.
turned ON Less than 45 Hz: Add 0.5% of reading.
Temperature coefficient Add: ±0.03% of reading/°C within the range 5 to 18°C or 28 to 40°C.
Accuracy when the Accuracy obtained by doubling the measurement range error for the accuracy when the
crest factor is set to 6 crest factor is set to 3.

Active Power Accuracy
Item Specifications

Accuracy Requirements

Same as the conditions for voltage and current.

• Power factor: 1

Accuracy (at 12 months)

(The accuracy shown below is the sum of reading and range errors.)
* f in the read error equation is the input signal frequency in kHz.

DC ±(0.1% of reading+0.2% of range) ±(0.3% of reading+0.2% of range)

≤

0.5Hz

f < 45Hz ±(0.3% of reading+0.2% of range) ±(0.3% of reading+0.2% of range)

≤ f ≤

45Hz

66Hz ±(0.1% of reading+0.1 % of range) ±(0.1% of reading+0.1 % of range)

≤

66Hz < f

1kHz ±(0.2% of reading+0.2 % of range) ±(0.2% of reading+0.2 % of range)

≤

1kHz < f

10kHz

±[{0.067×(f–1)}% of reading]

≤

10kHz < f

≤

10kHz < f
±[{0.09×(f–10)}% of reading]

WT310, WT332, WT333, WT310HC

(Current EXT sensor input)

±(0.1% of reading+0.3 % of range)

20kHz ±((0.13*f)% of reading+0.5 % of range)

±(0.5 % of reading+0.5 % of range)

100kHz

≤ f ≤

100kHz

≤ f ≤

100kHz

≤ f ≤

100kHz

≤ f ≤

100kHz

≤ f ≤

100kHz

≤ f ≤

100kHz

WT310HC (Current Direct input)

±((0.13*f)% of reading+0.3 % of range)

Key Features Applications Software & Tool Specification

08

09

Specification

Specification

• Influence of temperature changes after zero-level compensation or range change
Add the product of the voltage influence and the current influence listed below to the DC power accuracies.
DC voltage accuracy: 0.02% of range/°C��
DC current accuracies
WT310 (5mA/10mA/20mA/50mA/100mA/200mA ranges): 5uA/°C��
WT310 (0.5A/1A/2A/5A/10A/20A ranges) and WT330 direct current input: 500uA/°C��
WT310HC direct current input: 1mA/°C��
External current sensor input (/EX1): 1mV/°C��
External current sensor input (/EX2): 50uV/°C��

• Influence of self-generated heat caused by voltage input
Add 0.0000001 ×U2% of reading to the AC power accuracies.
Add 0.0000001 ×U2% of reading + 0.0000001 ×U2% of range to the DC power accuracies. U is the voltage reading

(V).

Influence of self-generated heat caused by voltage input lasts until falling the temperature of the input resistor even

if voltage input decreases.

• Influence of self-generated heat caused by current input
WT310:
Add 0.00013 × I2% of reading to the AC power accuracies.
Add 0.00013 × I2% of reading + 0.004 × I2 mA (0.5A/1A/2A/5A/10A/20A range) or 0.00013× I2% of reading +

0.00004 × I2 mA (5mA/10mA/20mA/50mA/100mA/200mA range), to the DC power accuracies. I is the current

reading (A).
WT310HC:
Add 0.00006 × I2% of reading to the AC power accuracies.
Add 0.00006 × I2% of reading + 0.001 × I2 mA to the DC power accuracies. I is the current reading (A).
WT330:
Add 0.00013 × I2% of reading to the AC power accuracies.
Add 0.00013 × I2% of reading + 0.002 × I2 mA to the DC power accuracies. I is the current reading (A).
Influence of self-generated heat caused by current input lasts until falling the temperature of the shunt resistor even

if current input decreases.

• Accuracy changes caused by data update interval
When the data update interval is 100 ms, add 0.05% of reading to 0.5Hz to 1kHz accuracy.

• Guaranteed accuracy ranges for frequency, voltage, and current
All accuracy figures for 0.5 to 10 Hz are reference values
The power accuracy figures for DC, 10 Hz to 45 Hz, and 400 Hz to 100 kHz when the current exceeds 20 A are

reference values.
Influence of power factor When power factor (λ) = 0(S: apparent power)

• ±0.2% of S for 45 Hz

• ±{(0.2 + 0.2 × f)% of S} for up to 100 kHz as reference data.
f is frequency of input signal in kHz.
When 0 < λ < 1 (Ø: phase angle of the voltage and current)
(power reading) × [(power reading error %) +
(power range error %) × (power range/indicated apparent power value) +
{tanØ× (influence when λ = 0)%}]
When the line filter 45 to 66 Hz: Add 0.3% of reading.
is turned ON Less than 45 Hz: Add 1% of reading.
Temperature coefficient Same as the temperature coefficient for voltage and current.
Accuracy when the Accuracy obtained by doubling the measurement range error for the accuracy when
crest factor is set to 6 the crest factor is set to 3.
Accuracy of Voltage accuracy + current accuracy
apparent power S
Accuracy of Accuracy of apparent power +(� 1.0004 –
reactive power Q
Accuracy of power ±[(λ –λ /1.0002) + |cosØ – cos{Ø + sin

λ

Factor
when voltage and current are at the measurement range rated input
Accuracy of phase ±[|Ø – cos
difference Ø deg ± 1 digit
when voltage and current are at the measurement range rated input

Voltage, Current, and Active Power Measurements
Item Specifications
Measurement method Digital sampling method
Crest factor 3 or 6
Wiring system WT310, WT310HC (One element model)
Single-phase, two-wire (1P2W)
WT332 (Two element model)
Select from single-phase, two-wire (1P2W); single-phase,
three-wire (1P3W); or three-phase,three-wire (3P3W)
WT333 (Three element model)
Select from single-phase, two-wire (1P2W); single-phase,
three-wire (1P3W); three-phase,three-wire (3P3W); three-phase,
four-wire (3P4W); or three-voltage, three-current (3V3A).
Range select Select manual or auto ranging.
Auto range Range increase

• The range is upped when any of the following conditions is met.

• Urms or Irms exceeds 130% of the currently set measurement range.

• Crest factor 3: Upk, Ipk value of the input signal exceeds 300% of the currently set
measurement range.

• Crest factor 6: Upk, Ipk value of the input signal exceeds 600% of the currently set
measurement range,
On the WT330, when any of those input elements meets the above condition, the
range is increased the next time the measured value is updated.
Range decrease

• The range is decreased when all of the following conditions are met.

• Urms or Irms is less than or equal to 30% of the measurement range.

• Urms or Irms is less than or equal to 125% of the next lower measurement range.

• Crest factor 3: Upk, Ipk value of the input signal exceeds 300% of the currently set
measurement range.

• Crest factor 6: Upk, Ipk value of the input signal exceeds 600% of the currently set
measurement range.
On the WT330, when all of the input elements meet the above condition, the range
is downed down the next time the measured value is updated.
Display mode Select RMS (the true RMS value of voltage and current),
Switching VOLTAGE MEAN (the rectified mean value calibrated to the RMS value of the voltage
and the true RMS value of the current), DC (simple average of voltage and current).
Measurement Select voltage, current, or the entire period of the data update interval for the signal
synchronization source used to achieve synchronization during measurement.
Line filter Select OFF or ON (cutoff frequency at 500 Hz).
Peak measurement Measures the peak (max,min) value of voltage, current or power from the
instantaneous voltage, instantaneous current or instantaneous power that is sampled.
Zero-level compensation Removes the internal offset of the WT310/WT310HC/WT332/WT333.

= 0%/100)}|] ± 1 digit

-1

≤ f ≤

(λ /1.0002)| + sin

66 Hz.

2

2

λ

λ

) (� 1 –

-1

(influence from the power factor when λ

-1

{(influence from the power factor when λ = 0%)/100}]

) × 100 % of range

Frequency Measurement
Item Specifications
Measured item Voltage and current frequencies applied to one selected input element can be measured.
WT332 (two element model)
Select voltage (U1)/ current (I1) of input element1 or
voltage (U3)/ current (I3) of input element3.
WT333 (three element model)
Select voltage (U1)/ current (I1) of input element1, voltage (U2)/ current (I2)
of input element2 or voltage (U3)/ current (I3) of input element3.
Method Reciprocal method
Frequency measuring range
Data Update Interval Measurement Range

0.1s 25Hz

0.25s 10Hz

0.5s 5Hz
1s 2.5Hz
2s 1.5Hz
5s 0.5Hz
Only for the direct current input of WT310HC, the maximum measurement range is
20kHz.
Measurement range Auto switching among six types: 1 Hz, 10 Hz, 100 Hz, 1 kHz, 10 kHz,
and 100 kHz.
Frequency filter Select OFF or ON (cutoff frequency of 500 Hz).
Accuracy Requirements
When the input signal level is 30% or more of the measurement range If the
crest factor is set to 3. (60% or more if the crest factor is set to 6)

• Frequency filter is ON when measuring voltage or current of 200 Hz or less.
Accuracy: ± (0.06% of reading)

Computation
Item Specifications
Computing equation of apparent power (S), reactive power (Q), power factor (λ), and phase angle (Ø)
i : input element number
Single-Phase, Three-Phase, Three-Voltage, Three-Phase,
Three-Wire (1P3W) Three-Wire (3P3W) Three-Current Four-Wire (3P4W)
Method (3V3A)
UΣ[V] (U1+U3)/2 (U1+U2+U3)/3
IΣ[A] (I1+I3)/2 (I1+I2+I3)/3
PΣ[W] P1+P3 P1+P2+P3
SΣ[VA] Si=Ui×Ii S1+S3 S1+S2+S3

QΣ[var]

Qi=

λΣ λ

i=Pi/Si P
SΣ
Ø[°] Øi=cos

Si SΣ

On the WT310/WT310HC/WT332/WT333, S, Q, λ, and Ø are derived through the computation of the measured values

of voltage, current, and active power. Therefore, for distorted signal input, the value obtained on the
WT310/WT310HC/WT332/WT333 may differ from that obtained on other instruments that use a different method.

• If the voltage or current is less than 0.5% (less than or equal to 1% if the crest factor is set to 6) of the rated range,

zero is displayed for S or Q, and error is displayed for λ and Ø.

• For Q[var], when the current leads the voltage, the Q value is displayed as a negative value; when the current lags

the voltage, the Q value is displayed as a positive value. The value of QΣ may be negative, because it is calculated
from the Q of each element with the signs included.

D(LEAD)/G(LAG)) The lead and lag of the voltage and current inputs can be detected
Lead and lag detection correctly for the following:
(Phase angle Ø’ s • Sine waves
D (lead) and G (lag)) • When the measured value is 50% or more (100% or more when the crest factor is 6)
of the measurement range

• Frequency: 20 Hz to 2kHz(WT310HC: to 1kHz)

• Phase difference: ±(5° to 175°)
Scaling Set the current sensor transformation ratio, VT ratio, CT ratio, and power factor when
applying the external current sensor, VT, or CT output to the instrument.

• Significant digits: Selected automatically according to significant digits in the voltage
and current ranges.

• Selectable range: 0.001 to 9999
Averaging Select the method from the following two types.

• Exponential averaging method

• Moving average method
Select the attenuation constant for exponential averaging; select the sample number
from 8, 16, 32,and 64 for moving average.
Efficiency Computation of efficiency is possible on the WT332/WT333.
Crest factor Computes the crest factor (peak value/RMS value) of voltage and current.
Four arithmetic operation Six types of four arithmetic operations possible (A+B, A–B, A*B, A/B, A
Average active power Computes the average active power within the integrated period.
during integration

Integration
Item Specifications
Mode Select manual integration mode, standard integration mode, or repetitive integration
mode.
Timer Automatically stop integration by setting a timer.
Selectable range: 0 hours 00 minutes 00 seconds to 10000 hours 00 minutes 00
seconds (Set automatically to manual integration mode for 0 hours 00 minutes 00
seconds)
Count overflow WP: 999999MWh/-99999MWh, q: 999999MAh/-99999MAh
Holds the elapsed integration time and integration value and stops integration when
the elapsed time of integration reaches the maximum integration time of 10000 hours
or when the integrated value reaches the maximum or minimum displayable
integration value (999999M or –99999M).
Accuracy ±(Power accuracy (or current accuracy) + 0.1% of reading) (fixed range)
* In the case of auto range:
The measurement is not carried out during a range change.
The first measurement data after the range change is added for the Period which
measurement was not carried out.
Range setting Auto range or fixed range for Integration is available
For details on range switching, see section of Voltage, Current, and Active Power
Measurements.
Valid Frequency Active power
Ranges for Integration DC to 45 kHz
Current
When the measurement mode is RMS:
DC, lower limit frequency determined by the data update interval to 45 kHz
When the measurement mode is VOLTAGE MEAN:
DC, lower limit frequency determined by the data update interval to 45 kHz
When the measurement mode is DC:
DC to 45 kHz
Timer accuracy ±0.02%
Remote control Start, stop and reset operations are available using an external remote signal.
(applies to products with the /DA4 or /DA12 option)

Varies depending on the data update interval (see description given later) as follows.

≤ f ≤

100kHz

≤ f ≤

100kHz

≤ f ≤

100kHz

≤ f ≤

100kHz

≤ f ≤

50kHz

≤ f ≤

20kHz

3

(S1+S3)

2

2

Q1+Q3 Q1+Q2+Q3

i

i

S

P

-

Σ

-1

Pi cos-1 P

( ) ( )

Σ

2

3

(S1+S2+S3)

3

2

/B, and A/B2)

Harmonic Measurement (/G5 Option)
Item Specifications
Measured item All Installed elements.
Method PLL synchronization method
Frequency range Fundamental frequency of the PLL source is in the range of 10 Hz to 1.2k Hz.
PLL source Select voltage or current of each input element.

• Input level
50% or more of the rated measurement range when the crest factor is 3.
100% or more of the rated measurement range when the crest factor is 6.

• The frequency filter must be turned on when the fundamental frequency is
less than or equal to 200Hz.
FFT data length 1024
Window function Rectangular

Sample rate, window width, and upper limit of analysis
Fundamental Frequency Sample rate Window Width Upper Limit of* Analysis orders
10Hz ~ 75Hz f*1024 1 50
75Hz ~ 150Hz f*512 2 32
150Hz ~ 300Hz f*256 4 16
300Hz ~ 600Hz f*128 8 8
600Hz ~ 1200Hz f*64 16 4

*The upper limit of analysis orders can be decreased.
Accuracy

(The accuracy shown below is the sum of reading and range errors.)
When Line Filter is OFF
<WT310/WT332/WT333>
Frequency Voltage Current Power

≤

10Hz

f < 45Hz 0.15% of reading 0.15% of reading 0.15% of reading

+0.35% of range +0.35% of range +0.50% of range

≤ f ≤

45Hz
+0.35% of range +0.35% of range +0.50% of range
440Hz < f
+0.35% of range +0.35% of range +0.50% of range
1kHz < f
+0.45% of range +0.45% of range +0.60% of range

2.5kHz < f
+0.45% of range +0.45% of range +0.60% of range

<WT310HC>
Frequency Voltage Current Power
10Hz
+0.35% of range +0.35% of range +0.50% of range
45Hz
+0.35% of range +0.35% of range +0.50% of range
440Hz < f
+0.35% of range +0.35% of range +0.50% of range
1kHz < f
+0.45% of range +0.45% of range +0.60% of range

2.5kHz < f
+0.45% of range +0.45% of range +0.60% of range

The items listed below apply to all of the tables.

• When the crest factor is set to 3.

• When λ (the power factor) is 1.

• Power figures that exceed 1.2kHz are reference values.

• For the direct current range, add 10uA to the current accuracy and (10uA/direct current range)×100% of range to

• For the external current sensor range, add 100 µV to the current accuracy and (100uV/external current sensor range

• For nth harmonics component input, add ({n/(m + 1)}/50)% of (the nth harmonics reading) to the n + mth harmonics

• Add (n/500)% of reading to the nth component of the voltage and current, and add (n/250)% of reading to the nth

• The accuracy when the crest factor is 6 is the same as the accuracy when the crest factor is 3 after doubling the

• The guaranteed accuracy ranges for frequency, voltage, and current, are the same as the guaranteed ranges for

If the amplitude of the high frequency component is large, influence of approximately 1% may appear in certain

Because the influence depends on the size of the frequency component, if the frequency component is small with

Display
Item Specifications
Display type 7-segment LED
Simultaneous display 4 items
Maximum display During normal measurement
(display range)

Displayed item

U, I, P, S*, Q* 99999 9999
λ* 1.0000 to – 1.0000 1.000 to – 1.000
Ø* G180.0 to d180.0 G180.0 to d180.0
fU*, fI* 99999 9999
WP, WP±, q, q±

• When the unit is MWh or MAh 999999 999999
(–99999 for negative watt hour and ampere hour.)

• When the unit is other than MWh or MAh 99999 99999
TIME
Elapsed integration time Display A indication Display resolution
0 to 99 hours 59 minutes 59 seconds 0.00.00 to 99.59.59 1s
100 hours to 9999 hours 59 minutes 59 seconds 100.00 to 9999.59 1minute
10000 hours 10000 1 hour
Efficiency (WT330 only) 100.00 ~ 999.99 (%) 100.0 ~ 999.9 (%)
Crest factor 99999 9999
Four arithmetic operation 99999 9999
Average active power 99999 9999
Voltage peak 99999 9999
Current peak 99999 9999
Power Peak 99999 9999

440Hz 0.15% of reading 0.15% of reading 0.25% of reading

≤

1kHz 0.20% of reading 0.20% of reading 0.40% of reading

≤

2.5kHz 0.80%+ of reading 0.80%+ of reading 1.56% of reading

≤

5kHz 3.05% of reading 3.05% of reading 5.77% of reading

≤

f < 45Hz 0.15% of reading 0.15% of reading 0.35% of reading

≤ f ≤

440Hz 0.15% of reading 0.15% of reading 0.25% of reading

≤

1kHz 0.20% of reading 0.20% of reading 0.40% of reading

≤

2.5kHz 0.80%+ of reading 0.95%+ of reading 1.68% of reading

≤

5kHz 3.05% of reading 3.35% of reading 6.05% of reading

the power accuracy.

rating)× 100% of range to the power accuracy.

and n – mth harmonics of the voltage and current, and add ({n/(m + 1)}/25)% of (the nth harmonics reading) to the
n + mth harmonics and n – mth harmonics of the power.

component of the power.

measurement range.

ordinary measurement.

harmonics.

respect to the range rating, the influence is also negligible.

When the number of When the number of
displayed digits is 5 displayed digits is 4

Maximum display During harmonic measurement
(display range)

Displayed item

U, I, P 99999 9999
λ 1.0000 to –1.0000 1.000 to –1.000
Uhdf, Ihdf, Phdf 0.000 to 99.999 to 0.00 to 99.99 to

100.00 to 999.99% 100.0 to 999.9%
Uthd, Ithd 0.000 to 99.999 to 0.00 to 99.99 to

100.00 to 999.99% 100.0 to 999.9%
ØU, ØI

• Phase angle of the 1st fundamental current with respect to the 1st fundamental voltage.
G180.0 to d180.0 G180.0 to d180.0

• Phase angle of the 2nd harmonics and higher harmonic of voltage with respect to the
1st fundamental voltage –180.0 to 180.0 –180.0 to 180.0

• Phase angle of the 2nd harmonics and higher harmonics of current with respect to the
1st fundamental current –180.0 to 180.0 –180.0 to 180.0

Unit symbols m, k, M, V, A, W, VA, var, °, Hz, h±, TIME, %
Number of displayed digits
Data update interval Select 0.1 s, 0.25 s, 0.5 s, 1 s, 2 s, or 5 s.
Response time At maximum, 2 times the data update rate
(The time it takes to reach the accuracy of the final value when the displayed value
changed from 0 to 100% or 100 to 0% of the rated range)
Auto range monitor The indicator illuminates when the input signal meets the conditions for auto range
switching.
Overrange display Overrange “- - oL- -” is displayed for the following conditions.
When the measured value exceeds 140% of the rated range
*WT310HC: 40A range
When the measured value exceeds 110% of the rated range
Hold Holds the displayed value.
Single update Updates the displayed value once each time the SINGLE key is pressed during Hold.
MAX hold Holds the maximum displayed value of U, I, P, S, Q, U±pk, I±pk and P±pk.

Internal memory
Item Specifications
Measured data Recall the stored measurement data by a communication command.
Store interval
Data update interval or in the range of 1 s to 99 hrs 59 min 59 s.
There is no backup function of stored measurement data
Setup information Saves/Loads four patterns of setup information.

External Current Sensor Input (/EX1 and /EX2 options)
Item Specifications
Allows input of voltage output type current sensor signal. For detailed input specifications, see “Input.”
Measurement range of the /EX1 option:
Crest factor 3: 2.5V, 5V, 10V
Crest factor 6: 1.25V, 2.5V, 5V
Measurement range of the /EX2 option:
Crest factor 3: 50mV, 100mV, 200mV, 500mV, 1V, 2V
Crest factor 6: 25mV, 50mV, 100mV, 250mV, 500mV, 1V

D/A Output (/DA4, /DA12 Options)
Item Specifications
Output voltage ±5 V FS (approx. ±7.5 V maximum) against each rated value.
Number of output channels 4 outputs for products with the /DA4;
12 outputs for products with the /DA12 option
Output items Set for each channel.
U, I, P, S, Q, λ, Ø, fU, fI, Upk, Ipk, WP, WP±, q, q± and MATH
Accuracy ±(accuracy of each measurement item + 0.2% of FS)(FS=5V)
D/A conversion resolution 16 bits
Minimum load 100 k
Update Interval Same as the data update interval.
Temperature coefficient ±0.05%/°C of FS

Remote Control Input/Output Signal (/DA4, /DA12 Options)
Item Specifications
Remote control input signal
Remote control output signal
I/O level TTL
I/O logic format Negative logic, falling edge

GP-IB Interface (Standard on -C1)
Item Specifications
Usable devices National Instruments Corporation

• PCI-GPIB or PCI-GPIB+, PCIe-GPIB or PCIe-GPIB+

• PCMCIA-GPIB or PCMCIA-GPIB+
(not support on Windows Vista or Windows 7)

• GPIB-USB-HS
Use driver NI-488.2M Ver. 2.8.1 or later.
Electrical and mechanical Complies with IEEE St’d 488-1978 (JIS C 1901-1987)

Serial (RS-232) Interface (Standard on -C2)
Item Specifications
Connector type D-Sub 9-pin (plug)
Electrical specifications Complies with EIA-574 (EIA-232 (RS-232) standard for 9-pin)
Baud rate Select from 1200, 2400, 4800, 9600, 19200, 38400 or 57600bps.

USB PC Interface
Item Specifications
Number of ports 1
Connector Type B connector (receptacle)
Electrical and Mechanical Complies with USB Rev. 2.0
specifications
Supported transfer modes HS (High Speed; 480 Mbps) and FS (Full Speed; 12 Mbps)
Supported protocols USBTMC-USB488 (USB Test and Measurement Class Ver. 1.0)
PC system requirements A PC with a USB port, running the English or Japanese version of Windows 7
(32 bit/64bit), Windows Vista (32 bit), or Windows XP (32 bit, SP2 or later)
Dedicated driver will supplied from Yokogawa home page

Ethernet Interface (/C7 Options)
Item Specifications
Ports 1
Connector type RJ-45 connector
Electrical and Mechanical Complies with IEEE802.3
specifications
Transmission system Ethernet (100BASE-TX, 10BASE-T)
Transmission rate 100 Mbps max.
Communication protocol TCP/IP
Supported services DHCP, remote control (VXI-11)

Select 5 or 4 digits

Ω

EXT HOLD, EXT TRIG, EXT START, EXT STOP, EXT RESET

INTEG BUSY

When the number of When the number of
displayed digits is 5 displayed digits is 4

Key Features Applications Software & Tool Specification

10

11

Specification

General Specifications
Item Specifications
Warm-up time Approx. 30 minutes
Operating environment Temperature: 5°C to 40°C
Humidity: 20%RH to 80%RH (No condensation)
Elevation: 2000m or less
Installation location Indoors
Storage environment Temperature: −25°C to 60°C
Humidity: 20%RH to 80%RH (No condensation)
Rated supply voltage 100 VAC to 240 VAC
Permitted supply 90 VAC to 264 VAC
range voltage
Rated supply frequency 50/60 Hz
Permitted supply voltage 48 Hz to 63 Hz
frequency range
Maximum power WT310, WT310HC: 50VA, WT332/WT333: 70VA
Consumption
External dimensions WT310, WT310HC: Approx. 213 (W) × 88 (H) × 379 (D) mm
(excluding protrusions.) WT332/WT333: Approx. 213 (W) × 132 (H) × 379 (D) mm
Weight WT310, WT310HC: Approx. 3 kg
WT332/WT333: Approx. 5 kg
Battery backup Setup parameters are backed up with a lithium battery.



Rack Mount

Model/parts number Product Description

751533-E2 Rack mounting kit For WT310 series EIA standalone installation
751533-J2 Rack mounting kit
751534-E2 Rack mounting kit
751534-J2
751533-E3
751533-J3
751534-E3
751534-J3

Ask Yokogawa for information on rack mounts in which WT310 and WT330 str combined.



Accessory (sold separately)

Model/parts number Product Description Order Q’ty

758917 Test lead set A set of 0.8 m long, red and black test leads 1
758922 Small alligator-clip Rated at 300 V and used in a pair 1
758929 Large alligator-clip Rated at 1000 V and used in a pair 1
758923 Safety terminal adapter (spring-hold type) Two adapters to a set 1

758931 Safety terminal adapter

758924 Conversion adapter BNC-banana-jack (female) adapter 1
366924 * BNC-BNC cable 1 m 1
366925 * BNC-BNC cable 2 m 1
758921 Fork terminal adapter Banana-fork adapter, Two adapters to a set 1
B9284LK
705926

Due to the nature of this product, it is possible to touch its metal parts. Therefore, there is a risk of electric shock,
so the product must be used with caution.
* Use these products with low-voltage circuits (42 V or less).



AC/DC Current sensor /Clamp on Probe

Model Product Name Description
CT1000
CT200
CT60
751552
96030
751574

* CT series do not conform CE Marking.
* For detailed information, see Power Meter Accessory Catalog Bulletin CT1000-00E

Rack mounting kit
Rack mounting kit
Rack mounting kit
Rack mounting kit
Rack mounting kit

External sensor cable
Connection Cable

AC/DC Current sensor
AC/DC Current sensor
AC/DC Current sensor
Clamp-on probe
Clamp-on probe
AC/DC Current sensor

For WT310 series JIS standalone installation
For WT310 series EIA connected installation
For WT310 series JIS connected installation
For WT330 series EIA standalone installation
For WT330 series JIS standalone installation
For WT330 series EIA connected installation
For WT330 series JIS connected installation

(screw-fastened type) Two adapters to a set

1.5 mm hex Wrench is attached

Current sensor input connector, Length 0.5 m
1 m, For DA4, DA12 option

DC~300 kHz, ±(0.05% of reading +30uA), 1000 Apk
DC~500 kHz, ±(0.05% of reading +30uA), 200 Apk
DC~800 kHz, ±(0.05% of reading +30uA), 60 Apk
30 Hz~5 kHz, 1400 Apeak(1000 Arms)
20 Hz~20 kHz, ±0.5% reading, 200 Arms
DC~100 kHz, 600 Apeak(400 Arms)

Order Q’ty



Model and Suffix Codes

Model SuppixCode Description
WT310 1 Input element model
Power Cord -D UL, CSA standard, PSE

-F VDE standard

-R AS standard

-Q BS standard

-H GB standard

-N NBR standard ( for Brazil )
Communication Interface -C1

*USB is standard -C2 RS- 232

Optional function /C7 Ethernet interface
/EX1
/EX2 External sensor input 50mV/100mV/200mV/500mV/1V/2V
/G5 Harmonics Measurement
/DA4 D/A- output(4CH)
Model Suppix-Code Describe
WT310HC 1 Input element /High current model
Power Cord -D UL, CSA standard, PSE

-F VDE standard

-R AS standard

-Q BS standard

-H GB standard

-N NBR standard ( for Brazil )
Communication Interface -C1

*USB is standard -C2 RS- 232

Optional function /C7 Ethernet interface
/EX1
/EX2 External sensor input 50mV/100mV/200mV/500mV/1V/2V
/G5 Harmonics Measurement
/DA4 D/A- output(4CH)
Model Suppix-Code Describe
WT332 2 Input elements model
WT333 3 Input elements model

1
1
1
1
1
1
1
1

1

1
1

Power Cord -D UL, CSA standard, PSE

-F VDE standard

-R AS standard

-Q BS standard

-H GB standard

-N NBR standard ( for Brazil )
Communication Interface -C1

*USB is standard -C2 RS- 232

Optional function /C7 Ethernet interface
/EX1
/EX2 External sensor input 50mV/100mV/200mV/500mV/1V/2V
/G5 Harmonics Measurement
/DA12 D/A- output(12CH)

Standard accessories
Power cord(1set), Rubber foot(1set), Current input protective cover(each 1 set), Start up guide(1set), Connector (provided only with

/DA4 or /DA12, each 1set), Safety terminal adapter 758931(provided two adapters in a set times input element number), CD
(1piece,included the startup guide, user guide, instruction manual and the communication manual by PDF data, and Viewer Software)

758917 Test lead set
Two leads in a set. Use 758917
in combination with 758922 or

758929. Total length: 75 cm
Rating: 1000 V, 32 A

1

758931 *
Safety terminal adapter set
Screw-fastened adapters. Two
adapters in a set. 1.5 mm Allen
wrench included for tightening.

Due to the nature of this product, it is possible to touch its metal parts. Therefore, there is a risk of electric shock, so the product must be
used with caution.
*1 Maximum diameters of cables that can be connected to the adapters 758923 core diameter: 2.5 mm or less; sheath diameter: 4.8 mm
or less 758931 core diameter: 1.8 mm or less; sheath diameter: 3.9 mm or less
*2 The coax cable is simply cut on the current sensor side. Preparation by the user is required.

758922 Small alligator adapters
For connection to measurement
leads (758917). Two in a set.
Rating: 300 V

2

B9284LK *
External Sensor Cable
For connection the external input
of the WT500 to current sensor.
Length: 50 cm

GP- IB

select one

External sensor input 2.5V/5V/10V

select one

GP- IB

select one

External sensor input 2.5V/5V/10V

select one

GP- IB

select one

External sensor input 2.5V/5V/10V

select one

758929 Large alligator adapters
For connection to measurement
leads (758917). Two in a set.
Rating: 1000 V

709526
26-pin cable for options DA4 and
DA12

1

758923 *
Safety terminal adapter set
(spring-hold type) Two adapters
in a set.

Notice

Before operating the product, read the user’s manual thoroughly for

proper and safe operation.

YOKOGAWA METERS & INSTRUMENTS CORPORATION

Global Sales Dept.

YOKOGAWA CORPORATION OF AMERICA

2 Dart Road, Newnan, GA. 30265-1094 U.S.A.
Phone: [phone] Facsimile: [phone]

YOKOGAWA EUROPE B. V.

Euroweg 2 3825 HD Amersfoort, THE NETHERLANDS
Phone: [phone] Facsimile: [phone]

YOKOGAWA ENGINEERING ASIA PTE. LTD.

5 Bedok South Road, Singapore 469270 SINGAPORE
Phone: [phone] Facsimile: [phone]

YOKOGAWA AMERICA DO SUL LTDA.

Praca Acapulco, 31-Santo Amaro, Sao Paulo/SP, BRAZIL CEP-04675-190
Phone: [phone]
Facsimile: [phone]

YOKOGAWA ELECTRIC KOREA CO., LTD.

C&M Sales Seoul Office
1301-1305, 13rd floor, Kolon digital tower, 106-1,
Yangpyongdong-5Ga, Yeongdeungpo-Gu, Seoul, 150-105,
KOREA
Phone: [phone] Facsimile: [phone]

Subject to change without notice. [Ed : 01/b] Printed in Japan, 301(KP)

All Rights Reserved, Copyright © 2013, Yokogawa Meters & Instruments Corporation.

YOKOGAWA AUSTRALIA PTY. LTD.

Tower A/112-118 Talavera Road Macquarie Park, NSW 2113
Australia
Phone: [phone] Facsimile: [phone]

YOKOGAWA INDIA LTD.

Plot No. 96. Electronic City Complex, Hosur Road, Bangalore 560100, INDIA
Phone: [phone] Facsimile: [phone]

YOKOGAWA SHANGHAI TRADING CO., LTD.

4F Tower D, Cartelo Crocodile Building, No.568 West Tianshan
Road, Shanghai, CHINA
Phone: [phone] Facsimile: [phone]

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P.O.BOX 10070, Manama, Building 577, Road 2516,
Busaiteen 225, Muharraq, BAHRAIN
Phone: [phone] Facsimile: [phone]

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Grokholskiy per. 13, Build. 2, 4th Floor, 129090, Moscow
RUSSIAN FEDERATION
Phone: [phone] Facsimile: [phone]

Tachihi Bld. No.2, 6-1-3 Sakaecho, Tachikawa-shi, Tokyo, 190-8586 Japan
Phone: [phone] Facsimile: [phone]

Represented by: