Hioki CM4371-50, CM4373-50, CM4375-50 Instruction Manual

CM4371-50

HIOKI CM4371C961-01

CM4373-50
CM4375-50

AC/DC CLAMP METER

Read carefully before use.

Keep for future reference.

Instruction Manual

EN

Mar. 2023 Revised edition 1
CM4371C961-01

[600625631]

Contents

HIOKI CM4371C961-01

Introduction .................................................................................................................1

Notations .....................................................................................................................3

Checking Package Contents .....................................................................................7

Options ........................................................................................................................8

Safety Information ....................................................................................................11

Operating Precautions .............................................................................................12

1 Overview 19

1.1 Product Overview and Features ..........................................................19

1.2 Part Names ............................................................................................20

2 Making Measurements 21

2.1 Inspection Before Measurement ..........................................................21

2.2 Installing Batteries and the Z3210 Wireless Adapter .........................22

Installation procedure ............................................................................................25

2.3 Use of Test Leads ..................................................................................27

L9300 Test Lead (accessory) .................................................................................29

CM4371C961-01

i

Contents

HIOKI CM4371C961-01

2.4 Current Measurement ...........................................................................32

2.5 Various Other Measurement Functions ..............................................42

2.6 LCD Backlight, Automatic Power Save (APS) ....................................46

2.7 DC High V Probe Mode .........................................................................47

2.8 Wireless communications function .....................................................51

2.9 Rotary Switch Combinations ...............................................................59

3 Specications 61

3.1 GeneralSpecications .........................................................................61

3.2 InputSpecications,MeasurementSpecications ...........................65

3.3 Accuracy table .......................................................................................75

ii

Manual hold, automatic hold ..................................................................................34

Switching the ranges .............................................................................................38

Filter function .........................................................................................................39

Maximum value, minimum value, average, and peak value ..................................40

Inrush current (inrush) ...........................................................................................41

Using GENNECT Cross .........................................................................................51

Z3210-to-Excel® direct data entry function

(Excel® direct input function, HID function) ............................................................55

4 Maintenance and Service 107

HIOKI CM4371C961-01

4.1 Troubleshooting ..................................................................................107

4.2 Error and Operation Displays ............................................................109

4.3 Cleaning ...............................................................................................110

5 Appendix 111

5.1 Voltage Detection Function ................................................................ 111

5.2 Example of Use ...................................................................................113

Index 115

WarrantyCerticate 119

Contents

iii

Contents

HIOKI CM4371C961-01

iv

Introduction

HIOKI CM4371C961-01

Thank you for choosing the Hioki CM4371-50/CM4373-50/CM4375-50 AC/DC Clamp Meter.
To ensure your ability to get the most out of this instrument over the long term, please read this
manual carefully and keep it available for future reference.
Read the separate document “Operating Precautions” carefully before using the instrument.

Latest edition of instruction manual

The contents of this manual are subject to change, for example as a result of

product improvements or changes to specications.

The latest edition as well as multilingual editions of the manual (in Chinese,
French, German, Italian Korean, and Spanish) can be downloaded from
Hioki’s website.

https://www.hioki.com/global/support/download

Product registration

Register your product in order to receive important product information.

https://www.hioki.com/global/support/myhioki/registration

Introduction

1

Introduction

HIOKI CM4371C961-01

Target audience

This manual has been written for use by individuals who use the product in question or who
teach others to do so. It is assumed that the reader possesses basic electrical knowledge
(equivalent to that of someone who graduated from the electrical program at a technical high
school).

Trademarks

• Microsoft Excel is a registered trademark or a trademark of Microsoft Corporation in the
United States and other countries.

• The Bluetooth
and any use of such marks by Hioki E.E. Corporation is under license. Other trademarks and
trade names are those of their respective owners.

2

®

word mark and logos are registered trademarks owned by Bluetooth SIG, Inc.

Notations

HIOKI CM4371C961-01

Safety notations

In this document, the severity levels of risk and hazard are classied as follows.

DANGER

WARNING

CAUTION

IMPORTANT

Indicates an imminently
hazardous situation that, if not
avoided, will result in death or
serious injury.

Indicates a potentially hazardous
situation that, if not avoided, could
result in death or serious injury.

Indicates a potentially hazardous
situation that, if not avoided, could
result in minor or moderate injury
or potential risks of damage to
the supported product (or to other
property).

Indicates information or content
that is particularly important from
the stand point of operating or
maintaining the instrument.

Notations

Indicates an action that must not
be performed.

Indicates an action that must be
performed.

Indicates a high-voltage hazard.
Failure to verify safety or improper
handling of the instrument could
lead to electric shock, burn injury,
or death.

Indicates the presence of a hazard
caused by a strong magnet. The
product could interfere with the
proper operation of electronic
medical devices such as
pacemakers.

3

Notations

HIOKI CM4371C961-01

Symbols shown on the instrument

Indicates the presence of a potential hazard. For more information about locations where this

symbol appears on instrument components, see the "Operating Precautions" (p. 12) and

the accompanying document entitled “Operating Precautions.”

Indicates that a dangerous voltage is generated from this terminal.

Indicates that the product can be attached or detached while the circuit is live.

Indicates the instrument is protected throughout by double insulation or reinforced insulation.

Indicates alternating current (AC).

Indicates direct current (DC).

Indicates the grounding terminal.

4

Symbols for various standards

HIOKI CM4371C961-01

Indicates that the product is subject to the Waste Electrical and Electronic Equipment (WEEE)
Directive in EU member nations.

Indicates that the product complies with standards imposed by EU directives.

Screen display

The instrument screen displays the alphanumeric characters as follows.

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

1 2 3 4 5 6 7 8 9 0

Notations

Exception

: Wire break detected

5

Notations

HIOKI CM4371C961-01

Accuracy labeling

Instrument accuracy is expressed by dening a percentage of the reading, a percentage of full scale, a

percentage of the setting, or a limit value for errors in terms of digits.

Reading

(display value)

Full scale

(maximum
display value)

Other notations

(p. )

*

CM4371

-50

6

Indicates the value displayed by the instrument.
Limit values for reading errors are expressed as a percentage of the reading (“% rdg”).

Indicates the maximum display value for each measurement range. Measurement range
values for the instrument indicates that maximum display value. Limit values for full-scale
errors are expressed as a percentage of full scale (“% f.s.”).

Indicates the page number to reference.

Indicates additional information is described below.

Indicates that the item is applicable to the CM4371-50 only.

Checking Package Contents

HIOKI CM4371C961-01

When you receive the instrument, inspect it to ensure that no damage occurred during

shipment. Pay particular attention to included accessories, panel keys, and terminals. If you nd
any damage or discover that the instrument does not perform as indicated in its specications,

please contact your authorized Hioki distributor or reseller.



AC/DC Clamp Meter

CM4373-50

CM4371-50

CM4375-50

Checking Package Contents



L9300 Test Lead

(p. 27)



C0203 Carrying Case



LR03 Alkaline batteries ×2



Instruction Manual
(this manual)

Please visit Hioki's website to
download other language versions in
PDF format.



Operating Precautions
(0990A907)

7

Options

HIOKI CM4371C961-01

Options

The options listed below are available for the instrument. To order an option, please contact your
authorized Hioki distributor or reseller.
Options are subject to change. Check Hioki’s website for the latest information.

Connection cables

When attaching the L4933 or L4934 to test leads, set the test leads

to the measurement category II conguration (for the L9207-10,

remove the sleeves).

L4933 Contact Pin Set*

3

L9300 Test Lead*

1

L9207-10 Test Lead*

8

1

L4934 Small Alligator Clip Set*

4

Options

HIOKI CM4371C961-01

L4930 Connection Cable Set*2

(length: 1.2 m)

L4931 Extension Cable Set*2

(length: 1.5 m,
with the coupling connector)

DT4910 Thermocouples (K)

P2000 DC High Voltage Probe*

*1: CAT IV 600 V, CAT III 1000 V, CAT II 1000 V, 10 A *7: CAT III 1000 V, 2 A
*2: CAT IV 600 V, CAT III 1000 V, 10 A *8: CAT III 600 V, CAT II 600 V, 10 A

*3: 30 V AC, 60 V DC, 3 A *9: CAT III 600 V, 10 A
*4: CAT III 300 V, CAT II 600 V, 3 A *10: CAT IV 1000 V, 2 A
*5: CAT II 1000 V, 1 A *11: CAT IV 1000 V, CAT III 2000 V
*6: CAT III 600 V, 5 A

L4935 Alligator Clip Set*

L9243 Grabber Clip*

L4936 Bus Bar Clip Set*

L4937 Magnetic Adapter Set*

9804 Magnetic Adapter*

L4932 Test Pin Set*

L4938 Test Pin Set*

11

L4939 Breaker Pin Set*

2

5

6

7

10

1

8

9

9

Options

HIOKI CM4371C961-01

Carrying cases

The instrument, test leads, and the instruction manuals can be accommodated.

C0203 Carrying Case C0207 Carrying Case

Z3210 Wireless Adapter

Connecting the Z3210 to the instrument enables the wireless

communication function.

See “2.8 Wireless communications function” (p. 51).

10

Safety Information

HIOKI CM4371C961-01

Measurement categories

The instrument conforms to the safety requirements for CAT III 1000 V and CAT IV 600 V
measuring instruments.

Service entrance

Service drop

CAT IV

(≤600 V)

Power meter

Distribution
panel

Internal wiring

CAT III

(≤1000 V)

Fixed installation

Safety Information

CAT II

(≤1000 V)

T

Outlet

11

Operating Precautions

HIOKI CM4371C961-01

Operating Precautions

Observe the following precautionary information to ensure that the instrument can be used

safely and in a manner that allows it to perform as described in its specications. Carefully

read the separate document entitled “Operating Precautions” before use. Use of the instrument

should conform not only to its specications, but also to the specications of all accessories,

options, and other equipment in use.

Do not touch the section beyond the barrier during operation.

Do not measure any current in excess of the derating curve.

12

DANGER

Failure to do so could cause the operator to experience an electric shock.

See “1.2 Part Names” (p. 20).

Doing so can cause overheating of the sensor, resulting in bodily injury, re, or

damage to the instrument.

See "Frequency derating characteristics" (p. 68).

The maximum measurement current varies with the frequency, and the current
that can be measured continuously is limited. Operating the instrument at less
than this limitation is referred to as derating.

Inspect the instrument and verify proper operation before

HIOKI CM4371C961-01

use.

Conrm that the white portion (insulation layer) inside the

cable is not exposed.

Operating Precautions

DANGER

Use of the instrument while malfunctioning could result in serious bodily injury.

If you nd any damage, contact your authorized Hioki distributor or reseller.
See “2.1 Inspection Before Measurement” (p. 21).

Using the instrument with a color inside its cable exposed could cause the
operator to experience an electric shock.

13

Operating Precautions

HIOKI CM4371C961-01

Do not allow the instrument to get wet.

Do not take measurements with wet hands.

When using the instrument while connected to test leads,

do not make measurements that exceed either of the ratings
indicated on the instrument or on the test leads, whichever is
lower.

14

WARNING

Failure to do so could cause the operator to experience an electric shock.

Using the instrument to make measurements that exceed either rating could
cause the operator to experience an electric shock.

IMPORTANT

HIOKI CM4371C961-01

Operating Precautions

Do not allow any foreign object to be caught between the

facing core surfaces of the jaws.

Do not scratch the facing core surfaces of the jaws.

Do not touch the facing core surfaces of the jaws with your

ngers.

Do not insert any foreign object into the gap of the jaws.

Do not drop the instrument.

Do not subject the instrument to any shock.

Doing so may adversely a󰀨ect the measurement accuracy and open/

close operation.
Clamp the instrument around only one conductor. Clamping the instrument
around two or more of conductors in a bundle prevents the instrument from
measuring any current regardless of whether the measurement target is a
single-phase or three-phase circuit.

15

Operating Precautions

HIOKI CM4371C961-01

L4937 Magnetic Adapter Set / 9804 Magnetic Adapter (optional)

People with electronic medical devices such as pacemakers

should not use the magnetic adapter.

Keep the magnetic adapter away from the body.

16

DANGER

Failure to do so may a󰀨ect proper operation of the electric medical devices,

presenting a hazard to human life.

Do not drop the magnetic adapter.

HIOKI CM4371C961-01

Do not subject the magnetic adapter to mechanical shock.

Do not use the magnetic adapter in locations where it may be

exposed to rainwater, dust, or condensation.

Do not bring the magnetic adapter near magnetic storage devices,

such as oppy disks, magnetic cards, prepaid cards, or magnetized

tickets.

Do not bring the magnetic adapter near precision electronic

equipment, such as computers, TV screens, or electronic wrist
watches.

Operating Precautions

CAUTION

Doing so could damage the magnetic adapter.

Doing so could decompose or deteriorate the magnetic adapter. In addition,
diminished magnetic adhesion cause the instrument to drop, resulting in
damage to the instrument.

Doing so could damage such devices or data stored in them.

17

Operating Precautions

HIOKI CM4371C961-01

18

1

HIOKI CM4371C961-01

Overview

1.1 Product Overview and Features

This instrument is a clamp meter that can
perform true RMS measurement of current
simply by clamping it around a circuit. In
addition to current, it can measure voltage,
frequency, rush current, resistance, diode,
capacitance, temperature , and AC power.
Installing the Z3210 Wireless Adapter
(optional) to the instrument allows your mobile
device to display waveforms and measure
harmonics.

Measurement function list

DC current and DC voltage, DC
power

Electric charge detection

CM4371

-50

Capacitance, temperature

Continuity check, resistance, diode

Automatic AC/DC, AC voltage, DC
voltage, AC+DC voltage, frequency

Automatic AC/DC, AC current, DC
current, AC+DC current, frequency

CM4373

-50

19

Part Names

HIOKI CM4371C961-01

1.2 Part Names

Front Rear

1

2

(The illustration shows the CM4375-50.)

20

1 Operation grip

2 Fn key (allows you to choose a function)

3

4

5

6

7

8

9

10

11

12

3 Jaws

4 Barrier

5 Serial number (The serial number

consists of 9 digits. The rst two (from

the left) indicate the year of manufacture,
and the next two indicate the month of
manufacture.)

6 Rotary switch

See “Measurement function list” (p. 19).

7 HOLD key

8 LCD

9 Battery cover

10 Operation keys

11 Measurement terminals

12 Strap hole

2

NO

NONO

HIOKI CM4371C961-01

Making Measurements

2.1 Inspection Before Measurement

Check Inspection details Check Inspection details

The battery cover is closed and its screw



has been securely tightened.

There is no foreign matter on the



measurement terminals (p. 20).

The test leads are not broken (p. 43).



There is no damage to the test lead



insulation, and neither the white sheathing
nor metal conductor inside the wire are
exposed.

The instrument is neither damaged nor



cracked.

No segments are missing.



OK

1 Ω or less

(All segments appear)

21

Installing Batteries and the Z3210 Wireless Adapter

HIOKI CM4371C961-01

2.2 Installing Batteries and the Z3210 Wireless Adapter

Installing the Z3210 to the instrument enables the wireless communications function. (p. 51)

Before removing the battery cover, remove the instrument

from an object under measurement and set the rotary switch
to the OFF position.

22

WARNING

Failure to do so could cause the operator to experience an electric shock. When

the instrument is clamped around the object under measurement, the battery
contact terminals are regarded as high-voltage parts.

After replacing the batteries or installing/removing the Z3210

HIOKI CM4371C961-01

Wireless Adapter, install the battery cover and tighten the
screw, then use the instrument.

Secure the battery cover with the screw attached to the

instrument at the time of shipment.

Installing Batteries and the Z3210 Wireless Adapter

WARNING

Use of the instrument with the battery cover removed could result in bodily
injury.

If you have lost the screw or nd that the screw is damaged, please contact your

authorized Hioki distributor or reseller.

23

Installing Batteries and the Z3210 Wireless Adapter

HIOKI CM4371C961-01

CAUTION

Do not mix batteries of di󰀨erent ages or types.

Do not use a battery whose recommended service life has expired.

Do not reverse the battery polarity.

Do not leave the exhausted batteries in the instrument.

Doing so may cause the batteries to leak, damaging the instrument.

Use the specied type of batteries only (LR03 Alkaline batteries).

Remove the batteries when the instrument is not in use for an

extended period of time.

Doing so may cause the batteries to leak, damaging the instrument.

Before handling the Z3210, eliminate static electricity on your body

by touching any metallic part, such as a doorknob.

Failure to do so may cause static electricity to damage the Z3210.

• When the

ones in good time. The instrument may be turned o󰀨 when the display is backlighted or the
buzzer sounds. After use, be sure to turn o󰀨 the instrument.

• Dispose of the batteries in accordance with local regulations.

24

mark blinks, the batteries will be exhausted. Replace the batteries with new

Installing Batteries and the Z3210 Wireless Adapter

HIOKI CM4371C961-01

Installation procedure

Read the precautions before performing the procedure. (p. 22)

You will need:

Phillips screwdriver (No. 2)

Measurement value

adjusting screws ×3

Do not turn.

NO

Do not turn any screws except the battery cover screw.

After removing the battery cover, you will nd three screws, which are used to adjust

NO

measured values. Do not turn them because the instrument will not be able to perform
measurement accurately.

3, 4

LR03
Alkaline batteries ×2

2
7

22

77

Z3210

Protective cap

5

6

25

Installing Batteries and the Z3210 Wireless Adapter

HIOKI CM4371C961-01

Remove the instrument from an object under measurement and set the rotary

1

switch to the OFF position.

2

Loosen the screw and remove the battery cover.

3

Remove the old batteries (when replacing the batteries).

4

Install fresh batteries, observing the correct polarity.

When installing the Z3210 Wireless Adapter, go on to step 5.

When not installing the Z3210 Wireless Adapter, go on to step

5

Remove the protective cap from the instrument.

6

Install the Z3210 Wireless Adapter, observing the correct orientation.

7

Reattach the battery cover and tighten the screw.

26

.

7

2.3 Use of Test Leads

HIOKI CM4371C961-01

The L9300 Test Lead (accessory) or the L9207-10 Test Lead (optional) is used for measurement.

Depending on measurement locations, use Hioki’s optional measurement cables.

See “Options” (p. 8)

When using the instrument, use the test leads and options

specied by Hioki.

When measuring the power line voltage, use test leads that

satisfy the following conditions.

Failure to do so could cause the operator to experience an electric shock.

The optional test leads for this instrument comply with the EN 61010 safety

standard. Observe the measurement category and rated voltage indicated on the
test leads during use.

Use of Test Leads

WARNING

Using test leads and options other than those specied could cause bodily injury

or short circuit accidents.

• IEC 61010 or EN 61010 safety standard-compliant

• Rated for measurement category III or IV

• With the rated voltage higher than voltage being measured

27

Use of Test Leads

HIOKI CM4371C961-01

Do not bend the cables at temperatures of 0°C or lower. Do not pull

on the cables.

28

CAUTION

The cables can become rigid. Doing so could damage the insulation or cause a
wire break, resulting in an electric shock.

L9300 Test Lead (accessory)

HIOKI CM4371C961-01

See the precautions in “Use of Test Leads” (p. 27) as well.

Use the test leads with the correct measurement category

displayed.

Do not use the test leads if the metal pin is bent or the

protective nger guard does not slide properly.

Use of Test Leads

WARNING

Doing so could cause short circuit accidents.

29

Use of Test Leads

HIOKI CM4371C961-01

Switching the measurement category

Unlock the protective nger guard.

1

Rotate the grip to unlock, moving the  mark along the guide line.

Slide the protective nger guard.

2

30

Protective nger guard

mark



Slide the  mark along the
guide line.

Guide line

Lock the protective nger guard.

HIOKI CM4371C961-01

3

Rotate the grip to lock, moving the  mark
along the guide line.
Rotate the grip until it clicks, and make sure
that the  mark indicates [LOCKED].

Perform the above steps to switch over from measurement category II to measurement category
III or IV as well.

Use of Test Leads

31

Current Measurement

HIOKI CM4371C961-01

2.4 Current Measurement

11

22

Hold down for 1 s.

IMPORTANT

Always perform zero
adjustment to perform accurate
measurement.

32

Zero adjustment



33

Clamp the instrument around the wire.Rotate the rotary switch.

44

(Auto AC/DC)

Example:

3P3W circuit breaker (AC current range)

Current direction

Current direction
arrow

Match the current direction arrow
with the current direction.

(AC A)

(AC+DC A)(DC A)

(Freqency)

HzAUTO

Frequency detection range for AC current

HIOKI CM4371C961-01

Current Measurement

CM4371-50

CM4373-50

CM4375-50 — 5.0 A or more

DC voltage polarity check (p. 59)

If the measured value is negative, the buzzer will sound and the display will be backlighted in red.

(threshold: −10 A)

20.00 A range 4.00 A or more

600.0 A range 20.0 A or more

600.0 A range 40.0 A or more

2000 A range 200 A or more

33

Current Measurement

HIOKI CM4371C961-01

Manual hold, automatic hold

Manual hold Automatic hold

Illuminate

Press the HOLD key again to disable
the hold function.

34

The measured value



freezes.



Hold down for
1 s.

(

the value has stabilized)

Illuminate

The measured value freezes automatically.

Holding down the HOLD key for 1 s to disable the
automatic hold function.

Flash

Clamp the instrument
around the wire.

appears when

Remove

Automatic hold conditions

HIOKI CM4371C961-01

Displayed value will freeze when the following two conditions are satised at the same time:

• When the measured value uctuation stabilizes within the uctuation range described in the table on the
next page.

• When the measured value exceeds the threshold value described in the table on the next page (voltage,

current).
When the measured value is less than the threshold value described in the table on the next page (resistance,
continuity check, diode).

Measured

value

Suppose that the measured value has fallen below (voltage, current) or exceeded the threshold value
(resistance, continuity, diode) after the displayed value froze. When the two auto-hold conditions are met

again after that, refreshing measured values will stop.

Start

Automatic hold,

e.g., 100.0 A

(1)

End

Start

(2)

End

Start

Automatic hold

e.g., 99.0 A

(1) Not frozen automatically

(2) Not frozen automatically

Threshold value

e.g., 12.0 A

Time

End

Current Measurement

(Does not fall below threshold.)

(Does not exceed threshold.)

: Fluctuation range

: Measured value to be frozen



35

Current Measurement

HIOKI CM4371C961-01

Measurement

function*

Auto A
AC current
DC current
AC+DC current

1

Measurement

range

20.00 A range
(CM4371-50)

600.0 A range
(CM4371-50,
CM4373-50)

Fluctuation range Threshold value

Within 1.00 A 1.00 A

Within 12.0 A 12.0 A

36

1000 A range
(CM4375-50)

2000 A range
(CM4373-50)

Within 12.0 A
(When inputting more than

12.0 A)
Within 1.0 A
(When inputting more than

12.0 A)

Within 40 A 40 A

12.0 A
(When inputting more than

12.0 A)

0.9 A
(When inputting more than

12.0 A)

Measurement

HIOKI CM4371C961-01

function*

Auto V*
AC voltage
DC voltage*
AC+DC voltage

DC High V Probe Mode 600.0 V range Within 12.0 V 80.0 V

1

2

2

Measurement

range

6.000 V,

60.00 V, 600.0 V

range

1000 V range Within 20 V 20 V

2000 V range Within 20 V 80 V

Fluctuation range Threshold value

Within 120 counts 120 counts

Current Measurement

Continuity check
Resistance

Diode 1.800 V range Within 0.040 V 1.460 V

*1: The automatic hold function does not support measurement functions not listed in this row.

*2: Except the 600.0 mV range (only when the range is set manually)

600.0

6.000 k

60.00 k

600.0 k

6.000 M

range,

Ω

range,

Ω

range,

Ω

range,

Ω

Ω

Within 100 counts 4900 counts

range

37

Current Measurement

HIOKI CM4371C961-01

Switching the ranges

When the CM4373-50 measures current

Automatic range Manual 2000 A rangeManual 600.0 A range

When the CM4371-50 measures current

Automatic range Manual 600.0 A rangeManual 20.00 A range

The CM4375-50 provides the 1000 A range only.

38

Filter function

HIOKI CM4371C961-01

Filter o󰀨 Filter on

Measured value including noise Measured value with reduced noise

Frequency characteristics when the lter

function is enabled

(100 A input)

Measured value (A)

Filter o󰀨

Filter on, pass band 100 (Hz)

Frequency (Hz)

Hold down
for 1 s.

Current Measurement

Disable the lter function when performing

measurement of power supply frequencies

in excess of 100 Hz, for example, on an

aircraft or ship.

Filter o󰀨

39

Current Measurement

HIOKI CM4371C961-01

Maximum value, minimum value, average, and peak value

11

Clamp the instrument
around the wire.

MAX, MIN, AVG,

22

(Auto AC/DC)

(AC A)

(AC+DC A)(DC A)

HzAUTO

(Frequency)

and PEAK are
unavailable in Auto
AC/DC mode.

33

44

The instrument
measures RMS
values.

AVG indicates
the average of all
measured values.

40

The measured value



freezes.

Peak min.

Peak max.

Max.

Hold down for 1 s.

Cancel



Wavwform

Min.

Measured
value

(RMS)

Display refresh
interval

Inrush current (inrush)

HIOKI CM4371C961-01

Current Measurement

11

Turn o󰀨 the motor.

22

Rotate the rotary switch.

33

Hold down for 1 s.

Clamp the instrument

44

around the wire.

See “Inrush trigger level” (p. 67).

55

Set the range.

See “Switching the ranges” (p. 38).

In automatic ranging mode, the instrument

will be automatically set to the 600.0 A range
(CM4371-50), 2000 A range (CM4373-50).

Zero adjustment



66

Hold down for 1 s.

Inrush on



77

Turn the motor on.

To exit inrush mode

Hold down
for 1 s.

RMS value (inrush)

e.g., 100 A

AC current

e.g., 250 A

AC inrush peak value

Inrush current occurrence period

(about 10 ms to 999 ms)

(Inrush current occurs)

RMS value (inrush)

DC current

AC inrush peak value

Inrush current occurrence period

(about 10 ms to 999 ms)

41

Various Other Measurement Functions

HIOKI CM4371C961-01

2.5 Various Other Measurement Functions

Voltage measurement

e.g., Commercial power supply (AC voltage)

33

Switching ranges (p. 38)



11

11

Do not apply
excessive voltage.

NO

(Flash in red)

42

Black Red

Do not touch.

NO

22

AUTO

Hz

(Auto AC/DC)

(AC V)

(DC V)

(AC+DC V)

(Frequency)

DC voltage polarity check (p. 59)

If the measured value is negative, the buzzer
will sound and the display will be backlighted

in red. (threshold: −10 V)

Various Other Measurement Functions

HIOKI CM4371C961-01

Continuity check Resistance measurement Diode measurement

2

Zero adjudtment

2

Zero adjustment

1 1

Black

(Backlighted in red)

See the specications for the

short-circuit and open-circuit

detecting thresholds (p. 72).

Red

3

Hold down
for 1 s.

Black

Hold down
for 1 s.

3

Red

If resistance values of
coils, including motors and
transformers, measured with

the auto-ranging uctuate,

select the range manually.

Black

Red

43

Various Other Measurement Functions

HIOKI CM4371C961-01

Capacitance measurement Temperature measurement

Black Red

Type K thermocouples exhibit a physical
phenomenon known as short range ordering,
which can cause inaccurate measurements

in the range of 250°C to 600°C.

44

+−

Black Red

To switch the
temperature units,

see p. 60.

DT4910
Thermocouples (K)

: The DT4910 is broken

(or not connected).

Various Other Measurement Functions

HIOKI CM4371C961-01

Electric charge

detection

CM4371

See"5.1 Voltage Detection
Function" (p. 111)

Bring the jaw close a
power line.

To switch the sensitivity.
(High/low) (p. 101)

CM4373

-50

(Illuminate in red)

Simultaneous display of

DC current and DC voltage

-50



e.g., Checking a car battery
Switch the ranges using the

RANGE key.

RedBlack

CM4375-50

DC power

measurement

e.g., Maintenance for a

solar power system

RedBlack

45

LCD Backlight, Automatic Power Save (APS)

HIOKI CM4371C961-01

2.6 LCD Backlight, Automatic Power Save (APS)

LCD backlight Automatic power save

Backlight o󰀨

Backlight on

Automatically shut o󰀨 after 40 s

of inactivity

46

(Always on)
How to cancel: p. 59

After 15 minutes

of inactivity

You can turn the display back on by
pressing a key or by rotating the rotary
switch.

After 45 minutes of inactivity

The instrument is automatically turned o󰀨.

Set the rotary switch to the OFF position to restart.

2.7 DC High V Probe Mode

HIOKI CM4371C961-01

Use of the P2000 DC High Voltage Probe (optional) allows you to measure DC voltage of up to
2000 V (CAT III 2000 V, CAT IV 1000 V), such as open voltage of solar panels.

Do not use the P2000 to measure AC voltage.

Do not measure voltage that exceeds 2000 V DC.

Use the P2000 to measure voltage that exceeds 1000 V.

Connect the instrument and the P2000 together with the strap when

using the L4943.

DC High V Probe Mode

WARNING

The probe cannot accurately measure AC voltage. Improper measurement could

lead to electric shock. You can use the P2000 for DC voltage measurement

only.

Doing so could damage the instrument and the P2000, causing bodily injury.

Use of other probes could cause the operator to experience an electric shock.

CAUTION

The cables and plugs will be subjected to stress, damaging them.

47

DC High V Probe Mode

HIOKI CM4371C961-01

When using the L4943 Connection Cable Set*

33

11

Disconnect the clip* from the strap

buckle* as shown in the gure.

Clip

22

Attach the strap* to the P2000.

For details, see the P2000 Instructon manual.

Strap

Attach the strap buckle to the instrument
and connect it to the clip that you
attached to the P2000 with the strap.

*: Supplied with the P2000.

48

-2-2

-1-1

-3-3

When using the L4930 Connection Cable
Set or the L4931 Extension Cable Set
(optional)

Hang the P2000 in some way, such as using a

magnetic strap, not to subject the cables and
the plugs to stress.

Making Measurements

HIOKI CM4371C961-01

Rotate the rotary switch.

11

or

22

Hold down the two keys for

1 s as described below.

DC High V Probe mode On



Connect the P2000 DC High Voltage Probe to the

33

measurement terminals of the instrument.

44

Set the range.

See “Switching the ranges” (p. 38).

DC High V Probe Mode

55

N (−)

P (+)

P2000 probes

Flash

44

Red

Black

33

OUTPUT

55

Bring the probes into
contact with an object to
be measured.

49

DC High V Probe Mode

HIOKI CM4371C961-01

Saving the DC High V Probe mode settings

Turn o󰀨 the instrument, and then set the rotary switch to other than the OFF position while holding down the

two operation keys as described below.

• The DC High V Probe mode start-up setting can be toggled between on and o󰀨. (p. 59)

• When the DC High V Probe mode start-up is enabled, the instrument will start in the mode you last used.

50

(Any position)

2.8 Wireless communications function

HIOKI CM4371C961-01

Installing the Z3210 Wireless Adapter (optional) is required.
Concurrent use of GENNECT Cross and HID function (p. 55) is not available.

Using GENNECT Cross

Enabling the wireless communications function allows you to check and record the measured
data of the instrument, and create measurement reports using your mobile device. For details,

see the operation guide for the GENNECT Cross app (free of charge).

Wireless communications function

GENNECT Cross special site

https://gennect.net/en/cross/index

51

Wireless communications function

HIOKI CM4371C961-01

Using the wireless communications function

Connect the Z3210 Wireless Adapter (option) into the instrument. (p. 22)

1

Install GENNECT Cross on your mobile device.

2

Turn on the instrument.

3

Enable the wireless communications function.

4

When the instrument is turned on for the rst time after the Z3210 has been installed, the wireless

communications function will be enabled.

O󰀨

(Default

setting)

Start GENNECT Cross and register the connection of the instrument.

5

• When GENNECT Cross is started for the rst time (when there is no registered instrument), the
Instrument Settings screen appears.

• When the instrument is placed near your mobile device, its connection is registered automatically on

the Instrument Settings screen of GENNECT Cross (up to eight instruments).

• Wait for 5 to 30 s until the connection of the instrument is registered after turning on the instrument. If
the connection of the instrument is not registered after 1 minute has elapsed, restart GENNECT Cross
and the instrument.

Select a measurement function to perform measurement.

6

52

Hold down for 1 s.

appears:

Wireless communications
function enabled

O󰀨: Wireless communications function disabled

Blinks: During wireless communications

• The communication distance is about 10 m with a clear line of sight. The communicable

HIOKI CM4371C961-01

distance may vary greatly depending on the presence of an obstruction (wall or metallic

shielding object) and the distance between the oor (ground) and instrument. To ensure the
stable communication, make sure that the radio wave intensity is su󰀩cient.

• GENNECT Cross is free of charge. However, the customer is responsible for the cost to
download the application software and connect to the Internet when using the software.

• GENNECT Cross may not operate properly depending on the mobile device.

• The Z3210 uses the 2.4 GHz band wireless technology.

When there is a device that uses the same frequency band such as a wireless LAN (IEEE

802.11.b/g/n) near your mobile device, the communication may not be established.

When the instrument is placed on the oor or ground, the communication distance becomes shorter. It is
recommended that you move the instrument away from the oor or ground and place it on a desk or table

or hold it by hand.

Wireless communications function

53

Wireless communications function

HIOKI CM4371C961-01

Event recording function

The event recording function logs the data when a measured value exceeds a desired threshold
value, which can be set with GENNECT Cross. For details, see the operation guide for the

GENNECT Cross app (free of charge). The number of recorded events can be checked using

the instrument.

Hold down the

two keys for 1 s
as described
above.

54

Event count

display

• Up to 99 events can be recorded. If events has
reached 99, the event recording will stops.

When another event recording starts,

previously recorded data will be deleted.

• Some events with a duration time of less than

400 ms may not be accurately measured,

failing to detect them.*
* Current frequency, voltage frequency,

capacitance (400 ms to 4000 ms, depending
on measured value), temperature (type K
thermocouple) 2000 ms

Z3210-to-Excel® direct data entry function (Excel® direct input function,

HIOKI CM4371C961-01

HID function)

Concurrent use of GENNECT Cross and HID function is not available.

The human interface device (HID) prole, with which the Z3210 Wireless Adapter is equipped, is
a prole same as that wireless keyboards use.

HID ON

HID OFF

The setting whether the HID function has been enabled or disabled will not be saved in the

instrument but in the Z3210.

Wireless communications function

Preparatory to data entry, open an Excel® le on your mobile device or computer and

choose a cell. When the instrument’s display freezes, the measured values will be

entered on the cells. The use of this function with the automatic hold function enabled

comes in handy. (p. 34)

When you wish to use GENNECT Cross, disable the HID function.

Measured value is entered.

55

Wireless communications function

HIOKI CM4371C961-01

Conrming the HID setting

Remove the test leads from the object under measurement.

1

Set the rotary switch to the OFF position.

2

Connect the Z3210 Wireless Adapter (option) into the instrument. (p. 22)

3

Conrm the HID setting.

4

Make sure that the instrument is turned o󰀨, and then set the rotary switch to the TEMP position while

holding down the

The settings stored in the Z3210

will be displayed.

When [− − − − ] appears

Update the Z3210 rmware to the latest version using GENNECT Cross (version 1.8 or later)..

To change the HID setting, use the procedure on the following page.

56

key.

or

Changing the HID setting

HIOKI CM4371C961-01

Turn o󰀨 the instrument.

1

Chang the HID setting.

2

Make sure that the instrument is turned o󰀨, and then set the rotary switch to any position while holding

down both the

After exhibiting the following displays, the instrument is automatically turned o󰀨.

Turn on the instrument again.

3

The HID setting will be toggled.

Wireless communications function

key and the key.

(Any position)

The instrument is
automatically turned

o󰀨.

57

Wireless communications function

HIOKI CM4371C961-01

IMPORTANT

To switch over from the HID function to GENNECT Cross

If you start GENNECT Cross without canceling the paring between the mobile device and the

instrument, GENNECT Cross may not be able to recognize the instrument as a connectible

device. Follow the procedure below to reconnect the instrument to GENNECT Cross.
Use the Bluetooth

1. Disable the Z3210’s HID function. (p. 57)

2. Use the Instrument Setting of GENNECT Cross to reconnect the instrument.

Check Hioki’s website for the latest information.

https://z3210.gennect.net

58

®

setting of your mobile device to delete the instrument.

2.9 Rotary Switch Combinations

HIOKI CM4371C961-01

Rotary Switch Combinations

+

Auto-power save (APS) function cancel

DC current/voltage, polarity check on/o󰀨 Any position

LCD all segments display*
version number*

four digit)*
check (Z3210 required)*

Buzzer (on/o󰀨)

Automatic backlight shuto󰀨 (on/ o󰀨) Any position

DC High V Probe mode setting saving

(on/o󰀨)

Turn o󰀨 the instrument, and then turn it on again while holding down one or

two operation keys.

(Set the rotary switch to other than the OFF position)

1

, serial number*1, HID setting

Setting Procedure

1

1

, model number (only last

, rmware

1

Factory-

shipped

setting

Any position On Not saved

O󰀨 Saved

Any position − −

Any position On Saved

On Saved

O󰀨 Saved

Any position

Saving of

setting

59

Rotary Switch Combinations

HIOKI CM4371C961-01

Setting Procedure

Toggling the HID setting (on/o󰀨)
(Z3210 required)

Factory-

shipped

setting

− −*

Saving of

setting

2

Switching between the two temperature
units: degrees Celsius and degrees
Fahrenheit

*1: The screen display depends on the rotary switch position.

*2: The setting whether the HID function has been enabled or disabled will not be saved in the instrument but

in the Z3210.

60

Hold down for 1 s.

To switch the
temperature units

To save the setting

Hold down for 1 s.

Degrees

Celsius

Saved

3

HIOKI CM4371C961-01

Specications

3.1 General Specications

Operating
environment

Operating
temperature and
humidity range

Storage temperature
and humidity range

Indoor use, pollution degree 2, altitude up to 2000 m (6562 ft.)

−25°C to 65°C (−13°F to 149°F), 90% RH or less (non-condensing)

−30°C to 70°C (−22°F to 158°F), 90% RH or less (non-condensing, with batteries

removed)

61

General Specications

HIOKI CM4371C961-01

Dust resistance and
water resistance

Standards Safety EN 61010

62

IP20 (When measuring voltage under completely dry conditions, when measuring

current owing through a hazardous live conductor under completely dry

conditions)
IP50 (When measuring resistance under completely dry conditions)
IP54 (When measuring current owing through an insulated conductor, during

storage)

The protection rating for the enclosure of this instrument (based on EN60529) is
IP20*, IP50*, or IP54*.
* IP20, IP50, IP54:
This indicates the degree of protection provided by the enclosure of the device for
use in hazardous locations, entry of solid foreign objects, and the ingress of water.
2: Protected against access to hazardous parts with a ngers. The equipment

inside the enclosure is protected against entry by solid foreign objects larger
than 12.5 mm in diameter.

5: Protected against access to hazardous parts with wire measuring 1.0 mm

in diameter. Dustproof type (The penetration of dust cannot be prevented
completely, but quantities of dust that may hinder the stated operation of
equipment or safety cannot penetrate the enclosure.)

0: The equipment inside the enclosure is not protected against the harmful e󰀨ects

of water.

4: The equipment inside the enclosure is protected against the harmful e󰀨ects of

water splashed against the enclosure from any direction.

EMC EN 61326

Power supply LR03 Alkaline batteries ×2

HIOKI CM4371C961-01

Continuous
operating time

Dimensions*

3

Jaw dimensions CM4371

Jaw cross-sectional
minimum dimension

Rated supply voltage: 1.5 V DC × 2

1

-50

*

CM4371

About 40 hours (without the Z3210)
About 20 hours (with the Z3210 installed and wirelessly
communicating)

2

-50

*

CM4373

About 40 hours (without the Z3210)
About 24 hours (with the Z3210 installed and wirelessly
communicating)

2

-50

*

CM4375

About 40 hours (without the Z3210)
About 20 hours (with the Z3210 installed and wirelessly
communicating)

-50

CM4371

CM4373

CM4375

CM4373

CM4375

CM4375

-50

-50

-50

-50

-50

-50

Approx. 65W × 216H × 35D mm (2.56″W × 8.50″H × 1.38″D)

Approx. 65W × 250H × 35D mm (2.56″W × 9.84″H × 1.38″D)

Approx. 65W × 242H × 35D mm (2.56″W × 9.53″H × 1.38″D)

Approx. 69Wj × 14Dj mm (2.72″W × 0.55″D)

Approx. 92Wj × 18Dj mm (3.62″W × 0.71″D)

Approx. 53Wj × 20Dj mm (2.09″W × 0.79″D)

Approx. 9.5 mm (0.37″)

General Specications

63

General Specications

HIOKI CM4371C961-01

Maximum
measurable
conductor diameter

Weight CM4371

Product warranty
duration

Accessories p. 7

Options p. 8

*1: Other prescribed conditions

When measuring 10 A AC, with the LCD not backlighted, values for reference purposes at 23°C

*2: Other prescribed conditions

When measuring 100 A AC, with the LCD not backlighted, values for reference purposes at 23°C

*3: The Jaw is not included in the dimensions of width and depth but in that of height.

64

-50

CM4371

-50

CM4373

-50

CM4375

-50

-50

CM4373

-50

CM4375

3 years or until the jaw open/close cycles reaches 30,000, whichever comes rst

33 mm

φ

55 mm

φ

34 mm

φ

Approx. 340 g (12.0 oz., including batteries)

Approx. 530 g (18.7 oz., including batteries)

Approx. 350 g (12.3 oz., including batteries)

Input Specications, Measurement Specications

HIOKI CM4371C961-01

3.2 Input Specications, Measurement Specications

(1) Basic specications

Measurable range See “3.3 Accuracy table” (p. 75).

Maximum rated voltage
between terminals

Maximum rated line-to­ground voltage

Measurement method True RMS measurement

Measurement terminals COM terminal, V terminal

(2) Current measurement specications

1000 V AC (up to 1 kHz)
1000 V DC

600 V (measurement category IV)
1000 V (measurement category III)
Anticipated transient overvoltage: 8000 V

Maximum input current As per the frequency derating characteristics (p. 68)

Coupling type AC current*

1

Other current

measurement parameters

AC coupling

DC coupling

65

Input Specications, Measurement Specications

HIOKI CM4371C961-01

Display update rate*

Zero-display range Auto A, AC current,

Crest factor Auto A, AC current, AC+DC current, inrush current

66

2

Auto A, AC current,
DC current,
AC+DC current

Current frequency 0.3 to 5.0 times/s (depending on the frequency)

DC power 1 time/s

DC current + DC voltage 2.5 times/s

DC current,
AC+DC current

-50

CM4371

-50

CM4373

-50

CM4375

5 times/s

5 counts or less

20.00 A range

600.0 A range 3 (500.0 A or less)

600.0 A range 3 (500.0 A or less)

2000 A range 2.84 (1000 A or less)

1000 A range

7.5

2.5 (more than 500.0 A but 600.0 A or

less)

2.5 (more than 500.0 A but 600.0 A or

less)

1.42 (more than 1000 A but 2000 A or

less)

1.5 (1000 A or less)

Frequency detection

HIOKI CM4371C961-01

input level

Inrush trigger level CM4371

Peak detection time
width

*1: Does not apply to AC detection in Auto A mode.
*2: Does not include range switching time.
*3: 8.00 A or more for 1 Hz ≤ f ≤ 5 Hz
*4: 10.0 A or more for 1 Hz ≤ f ≤ 5 Hz

Input Specications, Measurement Specications

-50

CM4371

-50

CM4373

-50

CM4375

-50

-50

CM4373

-50

CM4375

1 ms or more (with lter disabled)

20.00 A range

600.0 A range

600.0 A range

2000 A range

1000 A range

20.00 A range +2.0 A or more

600.0 A range +10 A or more

600.0 A range +10 A or more

2000 A range +100 A or more

1000 A range +10 A or more

4.00 A or more*

3

20.0 A or more

40.0 A or more

200 A or more

5.0 A or more*

4

Otherwise, −2.0 A or less

Otherwise, −10 A or less

Otherwise, −10 A or less

Otherwise, −100 A or less

Otherwise, −10 A or less

67

Input Specications, Measurement Specications

HIOKI CM4371C961-01

Frequency derating characteristics

-50

CM4371

Current to be measured (A)

68

Inputting up to 1061 A of current is allowable for 1 minute or less.

Frequency (Hz)

(66 Hz or less)

-50

HIOKI CM4371C961-01

CM4373

-50

CM4375

Input Specications, Measurement Specications

Current to be measured (A)

Frequency (Hz)

Current to be measured (A)

Frequency (Hz)

69

Input Specications, Measurement Specications

HIOKI CM4371C961-01

(3) Voltage measurement specications

Overload protection 1100 V DC, 1100 V AC, or 2 × 10

Coupling type AC voltage*

Input impedance See “3.3 Accuracy table” (p. 75).

Display update rate*

Zero-display range Auto V, AC voltage,

Crest factor Auto V, AC voltage,

70

7

(Up to 1 minute of continuous application)

Other voltage measurement

parameters

2

Auto V, AC voltage,
DC voltage, AC + DC voltage

Voltage frequency 0.3 to 5.0 times/s (depending on frequency)

DC power 1 time/s

DC current + DC voltage 2.5 times/s

AC voltage + DC voltage

AC voltage + DC voltage

1

V·Hz, whichever is lower

AC coupling

DC coupling

5 times/s

5 counts or less

6.000 V range, 60.00 V range, 600.0 V range:
3 (4000 counts or less)
2 (more than 4000 counts but 6000 counts or less)

1000 V range:
2 (750 counts or less)

1.5 (more than 750 counts but 1000 counts or less)

Peak detection time

HIOKI CM4371C961-01

width

Frequency detection
input level

3

CMRR*

4

NMRR*

*1: Does not apply to AC detection in Auto V mode.
*2: Does not include range switching time.
*3: Dened for 1 k
*4: Dened assuming that the input frequency is 50 Hz or 60 Hz.

Input Specications, Measurement Specications

1 ms or more (with lter disabled)

10% or more of each range’s f.s.

AC voltage, AC+DC voltage 60 dB or more

DC voltage 100 dB or more

DC voltage 60 dB or more

unbalance assuming that the input frequency is 0 Hz, 50 Hz, or 60 Hz.

Ω

71

Input Specications, Measurement Specications

HIOKI CM4371C961-01

(4) Other measurement parameters

Overload protection 1000 V DC, 1000 V AC, or 2 × 10

Overload current At steady state: 30 mA or less

Display update rate* Capacitance 0.5 to 5 times/s (depending on the capacitance)

Response time Continuity check Open or short-circuit condition lasting for 0.5 ms or

Open terminal voltage Continuity check,

Short-circuit
detecting threshold

Open-circuit detecting
threshold

Stabilization time for
reference junction
compensation of
instrument

*: Does not include range switching time.

72

7

(Up to 1 minute of continuous application)

At transient state: 1.5 A or less

Temperature

(Type K thermocouple)

resistance, diode

±10 Ω (continuous beep, LCD backlighted in red)

25

Ω

±10

250

Ω

Ω

Up to 120 minutes
(Reference: when the instrument having a temperature of 23°C is left to stand in
ambient environments of 65°C for 60 minutes)

V·Hz, whichever is lower

1 time/s (including thermocouple wiring break check)

more can be detected.

2.0 V DC or less

Input Specications, Measurement Specications

HIOKI CM4371C961-01

(5) DC High V Probe mode (in combination with the P2000)*

1

Maximum rated line-to­ground voltage

Maximum rated voltage
between terminals

Overload protection Conform to the specications of the P2000.

Coupling type DC coupling

Combinatorial
measurement accuracy

*1: The specications above apply when both of the following two conditions are satised only: (1) the P2000

is connected, and (2) the instrument is in DC High V Prove mode.

Conform to the specications of the P2000.

Conform to the specications of the P2000.

• DC high voltage
See “(11) DC high voltage (DC High V Probe mode)” (p. 98) in “3.3
Accuracy table.”

• DC power
See “(18) DC power ” (p. 102) in “3.3 Accuracy table.”

73

Input Specications, Measurement Specications

HIOKI CM4371C961-01

(6) Accuracy specications

Accuracy
guarantee
conditions

Input condition for
accuracy table

Measurement
accuracy

E󰀨ects of
conductor
position*

Temperature
coe󰀩cient

*: At any position with respect to the jaw’s center-point.

74

Accuracy guarantee

duration

Accuracy guarantee
temperature and humidity

range

Accuracy guarantee of current measurement, continuity check, and resistance
measurement assumes that zero adjustment has been performed.
Temperature (Type K thermocouple) measurement requires use of the DT4910.

Sine wave input

See “3.3 Accuracy table” (p. 75).

-50

CM4371

CM4373

CM4375

Add [(measurement accuracy × 0.1)/°C] to measurement accuracy (outside the
temperature range of 23°C ±5°C).

Within ±1.5% rdg

-50

Within ±1.0% rdg

-50

Within ±1.5% rdg (for cables of φ11 mm or more)

1 year (duration for which accuracy shown in the
accuracy table is guaranteed)
3 years (duration for which 1.5 times accuracy shown in
the accuracy table is guaranteed), value for reference

purposes

23°C ±5°C (73°F ±9°F), 90% RH or less (non-condensing)

3.3 Accuracy table

HIOKI CM4371C961-01

(1) Auto A (AC/DC current automatic detection)

When AC is detected:
Conforms to the accuracy specications described in “(4) AC+DC voltage” (p. 82).
When DC is detected:
Conforms to the accuracy specications described in “(3) DC current” (p. 80).

(2) AC current

Measured value/MAX/MIN/AVG (CM4371

Range

(automatic

ranging

threshold)

20.00 A

(more

than 2000
counts)

600.0 A
(less than
180 counts)

Accuracy

guarantee range

(resolution)

1.00 A to 20.00 A
(0.01 A)

1.0 A to 600.0 A
(0.1 A)

Accuracy table

-50

)

Accuracy guarantee

frequency range

10 Hz ≤ f < 45 Hz ±1.8% rdg ±0.10 A ±2.3% rdg ±0.10 A
45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±0.08 A ±1.8% rdg ±0.08 A
66 Hz < f < 1 kHz ±2.0% rdg ±0.10 A

10 Hz ≤ f < 45 Hz ±1.8% rdg ±0.5 A ±2.3% rdg ±0.5 A
45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±0.3 A ±1.8% rdg ±0.3 A
66 Hz < f < 1 kHz ±2.0% rdg ±0.5 A −

Measurement accuracy

Filter disabled Filter enabled

−

75

Accuracy table

HIOKI CM4371C961-01

Measured value/MAX/MIN/AVG (CM4373

Range

(automatic

ranging

threshold)

600.0 A

(more

than 6000
counts)

2000 A
(less than
540 counts)

76

Accuracy

guarantee range

(resolution)

1.0 A to 30.0 A
(0.1 A)

30.1 A to 600.0 A
(0.1 A)

10 A to 1800 A
(1 A)

1801 A to 2000 A
(1 A)

-50

)

Accuracy guarantee

frequency range

10 Hz ≤ f < 45 Hz ±1.8% rdg ±1.0 A ±2.3% rdg ±1.0 A
45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±0.8 A ±1.8% rdg ±0.8 A
66 Hz < f < 1 kHz ±2.0% rdg ±1.0 A −
10 Hz ≤ f < 45 Hz ±1.8% rdg ±0.5 A ±2.3% rdg ±0.5 A
45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±0.3 A ±1.8% rdg ±0.3 A
66 Hz < f < 1 kHz ±2.0% rdg ±0.5 A −
10 Hz ≤ f < 45 Hz ±1.8% rdg ±5 A ±2.3% rdg ±5 A
45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±3 A ±1.8% rdg ±3 A
66 Hz < f < 1 kHz ±2.0% rdg ±5 A −
10 Hz ≤ f < 45 Hz ±2.8% rdg ±5 A ±3.3% rdg ±5 A
45 Hz ≤ f ≤ 66 Hz ±2.3% rdg ±3 A ±2.8% rdg ±3 A
66 Hz < f < 1 kHz − −

Measurement accuracy

Filter disabled Filter enabled

Measured value/MAX/MIN/AVG (CM4375

HIOKI CM4371C961-01

Range

1000 A 1.0 A to 30.0 A

(0.1 A)

30.1 A to 900.0 A
(0.1 A)

900.1 A to 999.9 A
(0.1 A)

Accuracy

guarantee range

(resolution)

Accuracy table

-50

)

Accuracy guarantee

frequency range

10 Hz ≤ f < 45 Hz ±1.8% rdg ±1.0 A ±2.3% rdg ±1.0 A
45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±0.8 A ±1.8% rdg ±0.8 A
66 Hz < f < 1 kHz ±2.0% rdg ±1.0 A −
10 Hz ≤ f < 45 Hz ±1.8% rdg ±0.5 A ±2.3% rdg ±0.5 A
45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±0.3 A ±1.8% rdg ±0.3 A
66 Hz < f < 1 kHz ±2.0% rdg ±0.5 A −
10 Hz ≤ f < 45 Hz ±2.3% rdg ±0.5 A ±2.8% rdg ±0.5 A
45 Hz ≤ f ≤ 66 Hz ±1.8% rdg ±0.3 A ±2.3% rdg ±0.3 A
66 Hz < f < 1 kHz ±2.5% rdg ±0.5 A −

Measurement accuracy

Filter disabled Filter enabled

77

Accuracy table

HIOKI CM4371C961-01

PEAK MAX/ PEAK MIN (CM4371-50)

Range

20.00 A ±1.0 A to ±150.0 A

600.0 A ±10 A to ±900 A

78

Accuracy guarantee range

(resolution)

(0.1 A)

(1 A)

±901 A to ±1500 A
(1 A)

Accuracy guarantee

frequency range

10 Hz ≤ f < 45 Hz ±1.8% rdg ±0.7 A
45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±0.7 A
66 Hz < f < 1 kHz ±2.0% rdg ±0.7 A
10 Hz ≤ f < 45 Hz ±1.8% rdg ±7 A
45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±7 A
66 Hz < f < 1 kHz ±2.0% rdg ±7 A
10 Hz ≤ f < 45 Hz ±5.5% rdg ±7 A
45 Hz ≤ f ≤ 66 Hz ±5.0% rdg ±7 A
66 Hz < f < 1 kHz ±5.7% rdg ±7 A

Measurement accuracy

PEAK MAX/ PEAK MIN (CM4373

HIOKI CM4371C961-01

Range

600.0 A ±10 A to ±1500 A

2000 A ±10 A to ±2300 A

PEAK MAX/ PEAK MIN (CM4375

Range

1000 A ±10 A to ±1000 A

-50

)

Accuracy guarantee range

(resolution)

(1 A)

(1 A)

±2301 A to ±2840 A
(1 A)

-50

)

Accuracy guarantee range

(resolution)

(1 A)

±1001 A to ±1500 A
(1 A)

Accuracy table

Accuracy guarantee

frequency range

10 Hz ≤ f < 45 Hz ±1.8% rdg ±7 A
45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±7 A
66 Hz < f < 1 kHz ±2.0% rdg ±7 A
10 Hz ≤ f < 45 Hz ±1.8% rdg ±7 A
45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±7 A
66 Hz < f < 1 kHz ±2.0% rdg ±7 A
10 Hz ≤ f < 45 Hz ±6.5% rdg ±7 A
45 Hz ≤ f ≤ 66 Hz ±6.0% rdg ±7 A
66 Hz < f < 1 kHz −

Accuracy guarantee

frequency range

10 Hz ≤ f < 45 Hz ±1.8% rdg ±7 A
45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±7 A
66 Hz < f < 1 kHz ±2.0% rdg ±7 A
10 Hz ≤ f < 45 Hz ±2.3% rdg ±7 A
45 Hz ≤ f ≤ 66 Hz ±1.8% rdg ±7 A
66 Hz < f < 1 kHz ±2.5% rdg ±7 A

Measurement accuracy

Measurement accuracy

79

Accuracy table

HIOKI CM4371C961-01

(3) DC current

Measured value/MAX/MIN/AVG (CM4371

Range

(automatic ranging threshold)

20.00 A
(more than 2000 counts)

600.0 A
(less than 180 counts)

Measured value/MAX/MIN/AVG (CM4373

Range

(automatic ranging threshold)

600.0 A
(more than 6000 counts)

2000 A
(less than 540 counts)

Measured value/MAX/MIN/AVG (CM4375

Range

1000 A ±1.0 A to ±30.0 A (0.1 A) ±1.3% rdg ±0.8 A

80

-50

)

Accuracy guarantee range

(resolution)

±1.00 A to ±20.00 A (0.01 A) ±1.3% rdg ±0.08 A

±1.0 A to ±600.0 A (0.1 A) ±1.3% rdg ±0.3 A

-50

)

Accuracy guarantee range

(resolution)

±1.0 A to ±30.0 A (0.1 A) ±1.3% rdg ±0.8 A
±30.1 A to ±600.0 A (0.1 A) ±1.3% rdg ±0.3 A
±10 A to ±2000 A (1 A) ±1.3% rdg ±3 A

-50

)

Accuracy guarantee range

(resolution)

±30.1 A to ±999.9 A (0.1 A) ±1.3% rdg ±0.3 A

Measurement accuracy

Measurement accuracy

Measurement accuracy

PEAK MAX/ PEAK MIN (CM4371

HIOKI CM4371C961-01

Range

20.00 A ±1.0 A to ±150.0 A (0.1 A) ±1.3% rdg ±0.7 A

600.0 A ±10 A to ±900 A (1 A) ±1.3% rdg ±7 A

PEAK MAX/ PEAK MIN (CM4373

Range

600.0 A ±10 A to ±1500 A (1 A) ±1.3% rdg ±7 A
2000 A ±10 A to ±2300 A (1 A) ±1.3% rdg ±7 A

PEAK MAX/ PEAK MIN (CM4375

Range

1000 A ±10 A to ±1000 A (1 A) ±1.3 % rdg ±7 A

-50

)

Accuracy guarantee range

(resolution)

±901 A to ±1500 A (1 A) ±5.0% rdg ±7 A

-50

)

Accuracy guarantee range

(resolution)

±2301 A to ±2840 A (1 A) ±6.0% rdg ±7 A

-50

)

Accuracy guarantee range

(resolution)

±1001 A to ±1500 A (1 A) ±1.8% rdg ±7 A

Measurement accuracy

Measurement accuracy

Measurement accuracy

Accuracy table

81

Accuracy table

HIOKI CM4371C961-01

(4) AC+DC voltage

Measured value/MAX/MIN/AVG (CM4371

Range

(automatic

ranging

threshold)

20.00 A

(more

than 2000
counts)

600.0 A
(less than
180 counts)

82

Accuracy

guarantee range

(resolution)

1.00 A to 20.00 A
(0.01 A)

1.0 A to 600.0 A
(0.1 A)

-50

)

Accuracy guarantee

frequency range

10 Hz ≤ f < 45 Hz ±1.8% rdg ±0.10 A ±2.3% rdg ±0.10 A
DC, 45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±0.13 A ±1.8% rdg ±0.13 A
66 Hz < f < 1 kHz ±2.0% rdg ±0.10 A

10 Hz ≤ f < 45 Hz ±1.8% rdg ±0.7 A ±2.3% rdg ±0.7 A
DC, 45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±1.3 A ±1.8% rdg ±1.3 A
66 Hz < f < 1 kHz ±2.0% rdg ±0.7 A −

Measurement accuracy

Filter disabled Filter enabled

−

Measured value/MAX/MIN/AVG (CM4373

HIOKI CM4371C961-01

Range

(automatic

ranging

threshold)

600.0 A
(more than
6000 counts)

2000 A
(less than
540 counts)

Accuracy

guarantee range

(resolution)

1.0 A to 30.0 A
(0.1 A)

30.1 A to 600.0 A
(0.1 A)

10 A to 1800 A
(1 A)

1801 A to 2000 A
(1 A)

Accuracy table

-50

)

Accuracy guarantee

frequency range

10 Hz ≤ f < 45 Hz ±1.8% rdg ±1.2 A ±2.3% rdg ±1.2 A
DC, 45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±1.8 A ±1.8% rdg ±1.8 A
66 Hz < f < 1 kHz ±2.0% rdg ±1.2 A −
10 Hz ≤ f < 45 Hz ±1.8% rdg ±0.7 A ±2.3% rdg ±0.7 A
DC, 45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±1.3 A ±1.8% rdg ±1.3 A
66 Hz < f < 1 kHz ±2.0% rdg ±0.7 A −
10 Hz ≤ f < 45 Hz ±1.8% rdg ±7 A ±2.3% rdg ±7 A
DC, 45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±13 A ±1.8% rdg ±13 A
66 Hz < f < 1 kHz ±2.0% rdg ±7 A −
10 Hz ≤ f < 45 Hz ±2.8% rdg ±7 A ±3.3% rdg ±7 A
DC, 45 Hz ≤ f ≤ 66 Hz ±2.3% rdg ±13 A ±2.8% rdg ±13 A
66 Hz < f < 1 kHz − −

Measurement accuracy

Filter disabled Filter enabled

83

Accuracy table

HIOKI CM4371C961-01

Measured value/MAX/MIN/AVG (CM4375

Range

1000 A 1.0 A to 30.0 A

84

Accuracy

guarantee range

(resolution)

(0.1 A)

30.1 A to 900.0 A
(0.1 A)

900.1 A to 999.9 A
(0.1 A)

-50

)

Accuracy guarantee

frequency range

10 Hz ≤ f < 45 Hz ±1.8% rdg ±1.2 A ±2.3% rdg ±1.2 A
DC, 45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±1.8 A ±1.8% rdg ±1.8 A
66 Hz < f ≤ 1 kHz ±2.0% rdg ±1.2 A −
10 Hz ≤ f < 45 Hz ±1.8% rdg ±0.7 A ±2.3% rdg ±0.7 A
DC, 45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±1.3 A ±1.8% rdg ±1.3 A
66 Hz < f ≤ 1 kHz ±2.0% rdg ±0.7 A −
10 Hz ≤ f < 45 Hz ±2.3% rdg ±0.7 A ±2.8% rdg ±0.7 A
DC, 45 Hz ≤ f ≤ 66 Hz ±1.8% rdg ±1.3 A ±2.3% rdg ±1.3 A
66 Hz < f ≤ 1 kHz ±2.5% rdg ±0.7 A −

Measurement accuracy

Filter disabled Filter enabled

PEAK MAX/ PEAK MIN (CM4371

HIOKI CM4371C961-01

Range

20.00 A ±1.0 A to ±150.0 A

600.0 A ±10 A to ±900 A

-50

)

Accuracy guarantee range

(resolution)

(0.1 A)

(1 A)

±901 A to ±1500 A
(1 A)

Accuracy table

Accuracy guarantee

frequency range

10 Hz ≤ f < 45 Hz ±1.8% rdg ±0.7 A
DC, 45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±0.7 A
66 Hz < f < 1 kHz ±2.0% rdg ±0.7 A
10 Hz ≤ f < 45 Hz ±1.8% rdg ±7 A
DC, 45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±7 A
66 Hz < f < 1 kHz ±2.0% rdg ±7 A
10 Hz ≤ f < 45 Hz ±5.5% rdg ±7 A
DC, 45 Hz ≤ f ≤ 66 Hz ±5.0% rdg ±7 A
66 Hz < f < 1 kHz ±5.7% rdg ±7 A

Measurement accuracy

85

Accuracy table

HIOKI CM4371C961-01

PEAK MAX/ PEAK MIN (CM4373

Range

600.0 A ±10 A to ±1500 A

2000 A ±10 A to ±2300 A

PEAK MAX/ PEAK MIN (CM4375

Range

1000 A ±10 A to ±1000 A

86

-50

)

Accuracy guarantee range

(resolution)

(1 A)

(1 A)

±2301 A to ±2840 A
(1 A)

-50

)

Accuracy guarantee range

(resolution)

(1 A)

±1001 A to ±1500 A
(1 A)

Accuracy guarantee

frequency range

10 Hz ≤ f < 45 Hz ±1.8% rdg ±7 A
DC, 45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±7 A
66 Hz < f < 1 kHz ±2.0% rdg ±7 A
10 Hz ≤ f < 45 Hz ±1.8% rdg ±7 A
DC, 45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±7 A
66 Hz < f < 1 kHz ±2.0% rdg ±7 A
10 Hz ≤ f < 45 Hz ±6.5% rdg ±7 A
DC, 45 Hz ≤ f ≤ 66 Hz ±6.0% rdg ±7 A
66 Hz < f < 1 kHz −

Accuracy guarantee

frequency range

10 Hz ≤ f < 45 Hz ±1.8% rdg ±7 A
DC, 45 Hz ≤ f ≤ 66 Hz ±1.3% rdg ±7 A
66 Hz < f < 1 kHz ±2.0% rdg ±7 A
10 Hz ≤ f < 45 Hz ±2.3% rdg ±7 A
DC, 45 Hz ≤ f ≤ 66 Hz ±1.8% rdg ±7 A
66 Hz < f < 1 kHz ±2.5% rdg ±7 A

Measurement accuracy

Measurement accuracy

(5) Current frequency, voltage frequency

HIOKI CM4371C961-01

Range (automatic ranging

threshold)

9.999 Hz
(more than 9999 counts)

99.99 Hz
(more than 9999 counts, less than
900 counts)

999.9 Hz
(less than 900 counts)

(6) Inrush current

Measured inrush value (CM4371

Range

20.00 A 3.00 A to 20.00 A

600.0 A 10.0 A to 600.0 A

Accuracy guarantee range

1.000 Hz to 9.999 Hz
(0.001 Hz)

1.00 Hz to 99.99 Hz
(0.01 Hz)

1.0 Hz to 999.9 Hz
(0.1 Hz)

-50

)

Accuracy guarantee range

(resolution)

(0.01 A)

(0.1 A)

Accuracy table

(resolution)

Accuracy guarantee

frequency range

DC, 20 Hz ≤ f ≤ 500 Hz ±5.0% rdg ±0.13 A

DC, 20 Hz ≤ f ≤ 500 Hz ±5.0% rdg ±1.3 A

Measurement accuracy

±0.1% rdg ±0.003 Hz

±0.1% rdg ±0.01 Hz

±0.1% rdg ±0.1 Hz

Measurement accuracy

87

Accuracy table

HIOKI CM4371C961-01

Measured inrush value (CM4373

Range

600.0 A 10.0 A to 600.0 A (0.1 A) DC, 20 Hz ≤ f ≤ 500 Hz ±5.0% rdg ±1.3 A
2000 A 100 A to 1800 A (1 A) DC, 20 Hz ≤ f ≤ 500 Hz ±3.3% rdg ±13 A

Measured inrush value (CM4375

Range

1000 A 10.0 A to 999.9 A (0.1 A) DC, 20 Hz ≤ f ≤ 500 Hz ±5.0% rdg ±1.3 A

88

-50

)

Accuracy guarantee range

(resolution)

1801 A to 2000 A (1 A) DC, 20 Hz ≤ f ≤ 66 Hz ±5.0% rdg ±13 A

-50

)

Accuracy guarantee range

(resolution)

Accuracy guarantee

frequency range

Accuracy guarantee

frequency range

Measurement accuracy

Measurement accuracy

Inrush peak value (CM4371

HIOKI CM4371C961-01

Range

20.00 A ±3.0 A to ±150.0 A (0.1 A) DC, 20 Hz ≤ f ≤ 500 Hz ±6.0% rdg ±1.0 A

600.0 A ±10 A to ±900 A (1 A) DC, 20 Hz ≤ f ≤ 500 Hz ±6.0% rdg ±10 A

Inrush peak value (CM4373

Range

600.0 A ±10 A to ±1500 A (1 A) DC, 20 Hz ≤ f ≤ 500 Hz ±6.0% rdg ±10 A
2000 A ±100 A to ±2300 A (10 A) DC, 20 Hz ≤ f ≤ 500 Hz ±6.0% rdg ±100 A

Inrush peak value (CM4375

Range

1000 A ±10 A to ±1000 A (1 A) DC, 20 Hz ≤ f ≤ 500 Hz ±6.0% rdg ±10 A

Accuracy table

-50

)

Accuracy guarantee range

(resolution)

±901 A to ±1500 A (1 A) DC, 20 Hz ≤ f ≤ 500 Hz ±9.7% rdg ±10 A

-50

)

Accuracy guarantee range

(resolution)

±2310 A to ±2840 A (10 A) DC, 20 Hz ≤ f ≤ 66 Hz ±8.0% rdg ±100 A

-50

)

Accuracy guarantee range

(resolution)

±1001 A to ±1500 A (1 A) DC, 20 Hz ≤ f ≤ 500 Hz ±8.0% rdg ±10 A

Accuracy guarantee

frequency range

Accuracy guarantee

frequency range

Accuracy guarantee

frequency range

Measurement accuracy

Measurement accuracy

Measurement accuracy

89

Accuracy table

HIOKI CM4371C961-01

(7) Auto V (AC/DC voltage automatic detection)

When AC is detected: Conforms to the accuracy specications described in “(10) AC+DC voltage” (p. 95).
When DC is detected: Conforms to the accuracy specications described in “(9) DC voltage” (p. 93).

(8) AC voltage

Measured value/MAX/MIN/AVG

Range

(automatic

ranging

threshold)

6.000 V
(more than
6000 counts)

90

Accuracy

guarantee

range

(resolution)

0.000 V to

0.299 V
(0.001 V)

0.300 V to

6.000 V
(0.001 V)

Accuracy guarantee

frequency range*

15 Hz ≤ f < 45 Hz ±1.5% rdg

45 Hz ≤ f ≤ 66 Hz ±0.9% rdg

66 Hz < f < 1 kHz ±1.5% rdg

15 Hz ≤ f < 45 Hz ±1.5% rdg

45 Hz ≤ f ≤ 66 Hz ±0.9% rdg

66 Hz < f < 1 kHz ±1.5% rdg

Measurement accuracy

1 *2

Filter disabled Filter enabled

±0.015 V

±0.013 V

±0.015 V

±0.005 V

±0.003 V

±0.005 V

±2.0% rdg
±0.015 V
±1.4% rdg
±0.013 V

−

±2.0% rdg
±0.005 V
±1.4% rdg
±0.003 V

−

Input

impedance*

±5%

3.2 M

Ω

±5%

3.2 M

Ω

3

Range

HIOKI CM4371C961-01

(automatic

ranging

threshold)

60.00 V
(more than
6000 counts,
less than 540
counts)

600.0 V
(more than
6000 counts,
less than 540
counts)

1000 V
(less than 540
counts)

*1: Accuracy within the frequency range of 15 Hz (inclusive) to 20 Hz (exclusive) is designed values.
*2: Within the frequency range of less than 45 Hz, the accuracy guarantee assumes a superposed DC voltage

of less than 500 V.

*3: Dened assuming that the 50 Hz AC is input.

Accuracy

guarantee

range

(resolution)

3.00 V to

60.00 V
(0.01 V)

30.0 V to

600.0 V
(0.1 V)

50 V to
1000 V
(1 V)

Accuracy guarantee

frequency range*

15 Hz ≤ f < 45 Hz ±1.5% rdg

45 Hz ≤ f ≤ 66 Hz ±0.9% rdg

66 Hz < f < 1 kHz ±1.5% rdg

15 Hz ≤ f < 45 Hz ±1.5% rdg

45 Hz ≤ f ≤ 66 Hz ±0.9% rdg

66 Hz < f < 1 kHz ±1.5% rdg

15 Hz ≤ f < 45 Hz ±1.5% rdg

45 Hz ≤ f ≤ 66 Hz ±0.9% rdg

66 Hz < f < 1 kHz ±1.5% rdg

Measurement accuracy

1 *2

Filter disabled Filter enabled

±0.05 V

±0.03 V

±0.05 V

±0.5 V

±0.3 V

±0.5 V

±5 V

±3 V

±5 V

±2.0% rdg
±0.05 V

±1.4% rdg
±0.03 V

−

±2.0% rdg
±0.5 V

±1.4% rdg
±0.3 V

−

±2.0% rdg
±5 V

±1.4% rdg
±3 V

−

Accuracy table

Input

Ω

Ω

Ω

3

±5%

±5%

±5%

impedance*

3.1 M

3.0 M

3.0 M

91

Accuracy table

HIOKI CM4371C961-01

PEAK MAX/ PEAK MIN

Range

6.000 V 0 V to ±12.00 V

60.00 V ±3.0 V to ±120.0 V

600.0 V ±30 V to ±1000 V*

1000 V ±50 V to ±1000 V*

*1: Accuracy within the frequency range of 15 Hz (inclusive) to 20 Hz (exclusive) is designed values.
*2: Within the frequency range of less than 45 Hz, the accuracy guarantee assumes a superposed DC voltage

of less than 500 V.

*3: Values of up to ±1200 V are displayed, but accuracy is not dened for display values in excess of 1000 V

(values for reference purposes).

*4: Values of up to ±1500 V are displayed, but accuracy is not dened for display values in excess of 1000 V

(values for reference purposes).

92

Accuracy guarantee range

(resolution)

(0.01 V)

(0.1 V)

3

(1 V)

4

(1 V)

Accuracy guarantee
frequency range*

Measurement accuracy

1 *2

15 Hz ≤ f < 45 Hz ±1.8% rdg ±0.07 V
45 Hz ≤ f ≤ 66 Hz ±1.5% rdg ±0.07 V
66 Hz < f < 1 kHz ±1.8% rdg ±0.07 V
15 Hz ≤ f < 45 Hz ±1.8% rdg ±0.7 V
45 Hz ≤ f ≤ 66 Hz ±1.5% rdg ±0.7 V
66 Hz < f < 1 kHz ±1.8% rdg ±0.7 V
15 Hz ≤ f < 45 Hz ±1.8% rdg ±7 V
45 Hz ≤ f ≤ 66 Hz ±1.5% rdg ±7 V
66 Hz < f < 1 kHz ±1.8% rdg ±7 V
15 Hz ≤ f < 45 Hz ±1.8% rdg ±7 V
45 Hz ≤ f ≤ 66 Hz ±1.5% rdg ±7 V
66 Hz < f < 1 kHz ±1.8% rdg ±7 V

(9) DC voltage

HIOKI CM4371C961-01

Measured value/MAX/MIN/AVG

Range

(automatic ranging threshold)

600.0 mV
(more than 6000 counts)

6.000 V
(more than 6000 counts,
less than 540 counts)

60.00 V
(more than 6000 counts,
less than 540 counts)

600.0 V
(more than 6000 counts,
less than 540 counts)
1000 V
(less than 540 counts)

Accuracy guarantee range

(resolution)

0.0 mV to ±600.0 mV
(0.1 mV)

0.000 V to ±6.000 V
(0.001 V)

0.00 V to ±60.00 V
(0.01 V)

0.0 V to ±600.0 V
(0.1 V)

0 V to ±1000 V
(1 V)

Measurement

accuracy

±0.5% rdg
±0.5 mV
±0.5% rdg
±0.003 V

±0.5% rdg
±0.03 V

±0.5% rdg
±0.3 V

±0.5% rdg
±3 V

Accuracy table

Input impedance

(DC input)

±5%

6.7 M

Ω

±5%

6.7 M

Ω

±5%

6.1 M

Ω

±5%

6.0 M

Ω

6.0 M

±5%

Ω

93

Accuracy table

HIOKI CM4371C961-01

PEAK MAX/ PEAK MIN

Range Accuracy guarantee range (resolution) Measurement accuracy

600.0 mV 0 mV to ±1200 mV

6.000 V 0.00 V to ±12.00 V

60.00 V 0.0 V to ±120.0 V

600.0 V 0 V to ±1000 V

1000 V 0 V to ±1000 V

94

(1 mV)

±1.0% rdg ±7 mV

±1.0% rdg ±0.07 V

(0.01 V)

±1.0% rdg ±0.7 V

(0.1 V)

±1.0% rdg ±7 V

(1 V)

±1.0% rdg ±7 V

(1 V)

(10) AC+DC voltage

HIOKI CM4371C961-01

Measured value/MAX/MIN/AVG

Range

(automatic

ranging

threshold)

6.000 V
(more than 6000
counts)

60.00 V
(more than
6000 counts,
less than 540
counts)

Accuracy

guarantee

range

(resolution)

0.000 V to

0.299 V
(0.001 V)

0.300 V to

6.000 V
(0.001 V)

3.00 V to

60.00 V
(0.01 V)

Accuracy

guarantee

frequency range*

10 Hz ≤ f < 45 Hz ±1.5% rdg

DC,
45 Hz ≤ f ≤ 66 Hz
66 Hz < f < 1 kHz ±1.5% rdg

10 Hz ≤ f < 45 Hz ±1.5% rdg

DC,
45 Hz ≤ f ≤ 66 Hz
66 Hz < f < 1 kHz ±1.5% rdg

10 Hz ≤ f < 45 Hz ±1.5% rdg

DC,
45 Hz ≤ f ≤ 66 Hz
66 Hz < f < 1 kHz ±1.5% rdg

Measurement accuracy

Filter

1

disabled

±0.023 V
±1.0% rdg
±0.023 V

±0.023 V

±0.013 V
±1.0% rdg
±0.013 V

±0.013 V

±0.13 V
±1.0% rdg
±0.13 V

±0.13 V

Filter

enabled

±2.0% rdg
±0.023 V
±1.5% rdg
±0.023 V

−

±2.0% rdg
±0.013 V
±1.5% rdg
±0.013 V

−

±2.0% rdg
±0.13 V
±1.5% rdg
±0.13 V

−

Accuracy table

Input impedance*

DC: 6.7 M
AC: 3.2 M

DC: 6.7 M
AC: 3.2 M

DC: 6.1 M
AC: 3.1 M

Ω
Ω

Ω
Ω

Ω
Ω

±5%

±5%

±5%

±5%

±5%

±5%

2

95