Hioki 3227 Instruction Manual

INSTRUCTION MANUA

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322

7

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mΩ HiTESTE

R

Contents

Introduction i
Inspection

i

Safety Notes

ii

Notes on Use

iv

Organization of this Manual

vi

Chapter 1 Overview

1

1.1 Features 1

1.2 Specifications 2

1.2.1 General Specifications 2

1.2.2 Resistance Measurement

4

1.2.3 Temperature Measurements

5

1.2.4 Temperature Correction Function

5

1.3 Measurements and Working Systems 6

1.3.1 4-terminal Measurements 6

1.3.2 Temperature Probe

7

1.3.3 Measurement Value Display

10

1.3.4 Comparator Function

12

Chapter 2 Part Names 15

2.1 Front Panel 15

2.2 Rear Panel 16

2.3 Displays

17

2.4 Accessory and Options

18

Chapter 3 Unit Installation 19

3.1 Installing the Interfaces 19

3.2 Turning on the Power Supply 21

3.3 Selecting the Power Supply Frequency 23

3.4 Preparation for Measurements 24

3.4.1 Resistance Measurements 24

3.4.2 Temperature Correction and Temperature Measurements

25

3.5 Handle Operation 26

Chapter 4 Basic Operations 27

4.1 Operating Procedure 27

4.1.1 Function Classes 27

4.1.2 Key Shift States

28

4.1.3 Key Lock State

28

4.1.4 Remote State

28

4.1.5 Valid Input Key Table

29

4.2 Selecting the Measurement Mode 30

4.3 Resistance Measurement Mode 31

4.3.1 Selecting the Sampling Rate 31

4.3.2 Selecting the Measuring Range

32

4.3.3 Zero Adjustment

34

4.4 Resistance Measurement 35

4.5 Temperature Measurement

36

4.6 Holding the Measurement Value

37

Chapter 5 Applied Operations 39

5.1 Setting the Comparator 39

5.1.1 Setting the Comparator 1 39

5.1.2 Setting the Comparator 2

41

5.1.3 Eliminating the Comparator Table

42

5.2 Executing the Comparator 43

5.3 Setting the Temperature Correction

44

5.4 Executing the Temperature Correction

45

5.5 Setting the Temperature Conversion 46

5.6 Executing the Temperature Conversion 47

Chapter 6 External Control Terminals 49

6.1 Connector 49

6.1.1 Terminal Block 49

6.1.2 Digital I/O

50

6.2 Connecting Method 51

6.2.1 Terminal Block 51

6.2.2 Digital I/O

51

6.3 Electrical Specifications 53

6.3.1 Power Supply Rating 53

6.3.2 Input and Output Rating

53

6.3.3 Input and Output States

54

6.4 Using the Signals 58

6.4.1 Measurement Control 58

6.4.2 Outputting Measurement Results

61

Chapter 7 The Other Functions 63

7.1 System Resetting 63

7.2 Error Indications 64

Chapter 8 GP-IB Interface 67

8.1 Specifications 67

8.2 Setting the GP-IB Address 68

8.3 Introduction for the GP-IB 69

8.3.1 Messages 69

8.3.2 Command Syntax

70

8.3.3 Headers

70

8.3.4 Message Terminators

71

8.3.5 Separators

71

8.3.6 Data Formats

72

8.3.7 Abbreviation of Compound Command Type Header

73

8.3.8 Output Queue

73

8.3.9 Input Buffer

74

8.3.10 Status Model

74

8.3.11 Status Byte Register

75

8.3.12 Event Register

76

8.3.13 GP-IB Commands

78

8.4 Command Reference 79

8.5 Command Summary 109

8.5.1 Standard Command 109

8.5.2 Commands Specific to the 3227

110

8.6 Valid Command According to the Modes 113

8.7 Initialization 114

8.8 Notes on GP-IB Interface 115

8.9 Sample Programs 116

8.9.1 Hewlett Packard Series 300 Sample Programs 116

8.9.2 DOS/V Sample Program

124

Chapter 9 Printer Interface 127

9.1 Printer Interface 127

9.1.1 Connecter 127

9.1.2 Connecting Method

128

9.2 Print Method 129

Chapter 10 Maintenance and Service 131

10.1 Changing the Fuse 131

10.1.1 Power Fuse 131

10.1.2 Circuit Protection Fuse

132

10.2 Disposing the Unit 134

10.3 Trouble Shooting 135

i

────────────────────────────────────────────────────

Introduction

────────────────────────────────────────────────────

I

ntroduction

I

nspection

Thank you for purchasing this HIOKI "3227 mΩ HiTESTER." To get the
maximum performance from the unit, please read this manual first, and keep
this at hand.

When the unit is delivered, check and make sure that it has not been
damaged in transit. In particular, check the accessories, panel switches, and
connectors. If the unit is damaged, or fails to operate according to the
specifications, contact your dealer or HIOKI representative.

Accessories

9287 CLIP TYPE LEAD 1
9188 TEMPERATURE PROBE 1
Power code 1
Converter plug 1
Instruction Manual 1
Spare fuse for the circuit protection F1.0A/250V 1
Spare fuse for the power supply 1

T0.5A/250V (at 100/110/120V)

T0.25A/250V (at 200/220/240V)
(The spare fuse is stored inside the AC power supply inlet, and is of a rating
appropriate to the actual operational voltage of the unit.)

Shipment

If reshipping the unit, preferably use the original packing.

ii

────────────────────────────────────────────────────

Safety Notes

────────────────────────────────────────────────────

WARNIN

G

This equipment is designed to according to IEC 348 Safety Standards,
and has been tested for safety prior to shipment. Incorrect measurement
procedures could result in injury or death, as well as damage to the
equipment. Please read this manual carefully and be sure that you
understand its contents before using the equipment. The manufacturer
disclaims all responsibility for any accident or injury except that resulting
due to defect in its product.

・This symbol is affixed to locations on the equipment where the

operator should consult corresponding topics in this manual
(which are also marked with the

symbol) before using relevant

functions of the equipment.

・In the manual, this mark indicates explanations which it is

particularly important that the user read before using the
equipment.

Indicates AC (Alternating Current).

Indicates a fuse.

S

afety Notes

This Instruction Manual provides information and warnings essential for
operating this equipment in a safe manner and for maintaining it in safe
operating condition. Before using this equipment, be sure to carefully read the
following safety notes.

Safety symbols

iii

────────────────────────────────────────────────────

Safety Notes

────────────────────────────────────────────────────

WARNIN

G

Indicates that incorrect operation presents significant danger of
accident resulting in death or serious injury to the user.

CAUTIO

N

Indicates that incorrect operation presents possibility of injury to the
user or damage to the equipment.

NOTE

Denotes items of advice related to performance of the equipment or
to its correct operation.

The following symbols are used in this Instruction Manual to indicate the
relative importance of cautions and warnings.

iv

────────────────────────────────────────────────────

Notes on Use

────────────────────────────────────────────────────

WARNIN

G

In order to prevent electric shock and short-circuit accidents, shut off
the power to the line to be measured before connecting the direct
connection voltage and current cables to the terminals.

Be sure to connect the input terminal, SENSE, or SOURCE terminals
correctly. Measurement which is attempted with the wiring connected
incorrectly may cause damage to the unit or a short-circuit.

Before turning on the power, make sure that the voltage of the power
supply being used matches the supply voltage indicated on the rear
panel of the unit.

The unit is constructed so as to be connected to a ground line via a
three-core power cord that is supplied with the unit.

In order to avoid electric shock, connect the unit to a properly grounded
(3-pin) outlet using the power cord provided. In addition, if using a
ground adapter, be absolutely sure to connect the green ground wire
which protrudes from the adapter to a ground line.

In order to avoid electric shock, if not connecting the unit to a properly
grounded (3-pin) outlet using the power cord provided, be sure to
connect the ground terminal to a proper ground.

The maximum permissible input is mentioned on specifictioins. Do not
measure voltage in excess of these limitations, as doing so may damage
the unit or cause an accident that might result in infuty or death.

CAUTIO

N

・To avoid damage to the unit, do not input a voltage or current exceeding the

rated maximum to the external input terminals.

・To avoid damage to the unit, do not input a voltge or current exceeding the

rated to the output terminal.

・To avoid damage to the unit, do not subject the equipment to vibrations or

shocks during transport or handling. Be especially careful to avoid dropping
the equipment.

・Before using the unit, make sure that the sheathing on the probes is not

damaged and that no bare wire is exposed. If there is damage, using the
unit could cause electric shock. Replace the probe with the specified 9287.

・The unit should always be operated indoors in a range from 0℃ to 40℃ and

80% RH or less. Do not use the unit in direct sunlight, dusty conditions, or in
the presence of corrosive gases.

・Do not measure the voltage applied point. Particularly, the 3227 would be

damaged by induced voltage when measuring soon after the temperature
rise test or the pressure test of the trans or the motor.

N

otes on Use

In order to ensure safe operation and to obtain maximum performance from
the unit, observe the cautions listed below.

v

────────────────────────────────────────────────────

Notes on Use

────────────────────────────────────────────────────

NOTE

･ Always set the power supply frequency before measurement. When it has

been set incorrectly, inaccurate measurement would be performed. How to set
this, Section 3.3, "Selecting the Power Supply Frequency."

･ Accurate measurement may be impossible in locations subject to strong

external magnetic fields, such as transformers and high-current conductors, or
in locations subject to strong external electric fields, such as radio
transmission equipment.

･ For accurate measurement, allow the unit to warm up for 30 minutes before

starting the operation.

･ In the source of current (SOURCE), there is a fuse for the circuit protection. 

When it is ruptured, the measurement should be impossible.

･ Do not use such relay as dealing with the small signals, for fear of breaking

the pellicle of the contact point.

･ When the one that includes the L component such as the transformer for the

power supply a lot is measured a measured value may not stabilize.

vi

────────────────────────────────────────────────────

Organization of this Manual

────────────────────────────────────────────────────

O

rganization of this Manual

Chapter 1 Overview

Summary and features of the 3227

Chapter 2 Part Names

Description of part names

Chapter 3 Unit Installation

Preparation for measurements

Chapter 4 Basic Operations

Description of basic operations

Chapter 5 Applied Operations

Setting the comparator and the temperature correction

Chapter 6 External Control Terminals

Description of the external control terminals

Chapter 7 The Other Functions

System resetting and error indications

Chapter 8 GP-IB Interface

Specifications and commands of GP-IB

Chapter 9 Printer Interface

Use of the printer interface

Chapter 10 Maintenance and Service

Disposing and trouble shooting

Index

1

────────────────────────────────────────────────────

1.1 Features

────────────────────────────────────────────────────

Chapter

1

Overvie

w

1

.1 Features

(1) 10μΩ minimum high accuracy and high resolution resistance measurement,

by 4-terminal measurement

(2) High speed resistance measurement of 90 times/second in its top
(3) Connecting the temperature probe makes 0℃ to 40℃ temperature

measurement possible

(4) Auto range function is contained
(5) Measurement ranges can be selected from external control terminal.
(6) The components can be selected by the comparator. When changing the

measurement subjects, the 15 comparator tables set in advance make it
possible. They can also be selected by external control terminal.

(7) When connecting the temperature probe, the resistance temperature is able to

be corrected by optional temperature and resistance temperature coefficient.

(8) The temperature of the measured object can be displayed, by conversion from

the measured resistance. Either the temperature (t) or the temperature rise
(Δt) of the measured object can be selected for display.
A comparator can also be used to provide a pass/fail decision from the
displayed value.

(9) The unit can hold up to 15 sets (tables) of temperature conversions in memory.

The setting table can also be selected using the external control terminals.

(10) Trigger input, BCD output and comparator output make the unit match for

the line use.

(11) The measurement results can be printed with the 9203 DIGITAL PRINTER.

The results also can be shown as statistics. (option)

(12) Full remote control by GP-IB is possible (option).
(13) The measurement results can be printed to the centronics printer (option).

2

────────────────────────────────────────────────────

1.2 Specifications

────────────────────────────────────────────────────

1

.2.1 General Specifications

Measurement method and
operating method

4-terminal and dual integrator circuit

Maximum number of display digit

Resistance measurement "30000" 4 digit (3 digit when at FAST)
Temperature measurement "4000" 3 digit
Temperature conversion "±999.9" 4 digit

Sampling rate

Resistance measurement "SLOW" Approx. 4 times/second

"MEDIUM" Approx. 16 times/second
"FAST" Approx. 90 times/second

Temperature measurement Approx. 2 times/second

NOTE: When performing the comparator as reference value-per-range, in "FAST", the sampling rate

would be approximately 75 times/seconds

Response time

Resistance measurement "SLOW" Approx. 500 ms

"MEDIUM" Approx. 150 ms
"FAST" Approx. 50 ms

Auto range Contains (invalid when using the comparator)
Input over "OF" display
Comparator Set with each 15 table (selected by key operation and external

control)
Comparison method selection (HIGH/LOW, REF/%)
External control terminal mode selection (AUTO/EXT)
Buzzer mode selection (Hi/Lo, IN, OFF)
3-level (Hi, IN, Lo) fluorescent character display tube display,
external control output.

Temperature correction function Correctional temperature (0.00℃ to 40.00℃,32F to 104 F)

Standard temperature (-10.0℃ to 99.9℃,14F to 122 F)
Temperature coefficient (±9999ppm)
Optional settings are possible

Temperature conversion function Absolute temperature/temperature rise(Δt) selectable

initial resistance (0.00 mΩ to 300.00 kΩ)
initial temperature ( −10.0 ℃ to 99.9 ℃)
coefficient ( ±999.9)
Optional settings are possible

Maximum over load input 100 VDC or VAC rms (circuit protection by fuse)

1

.2 Specifications

3

────────────────────────────────────────────────────

1.2 Specifications

────────────────────────────────────────────────────

Dielectric strength

Between the case and the input
terminal

1.5 kVAC

Between the case and the powe

r

supply line

1.5 kVAC (sensitivity current: 5 mA)

Insulation resistance Between the case and the input terminal (for a minute)

Between the case and the power supply line (for a minute)
100 MΩ or more

External control

Open corrector output BCD 5 digit, measurement end, NG, comparator result
TTL input measuring range, comparator table, measurement trigger, print

,

zero adjustment, comparator output, temperature conversion
table

External interface The 9588 GP-IB INTERFACE (IEEE 488.2) (option)
Printer interface 9589 CENTRONICS (option)
Operating temperature/humidity 0℃ to 40℃ (32 Fto104F), 80% RH or less (no condensation)
Storage temperature/humidity -10℃ to 50℃ (14 Fto122F), 80% RH or less (no condensation)
Power supply and power

consumption

100, 110, 120, 200, 220, 240 VAC (±10%, 250 V MAX), 50/60 Hz,
maximum 40 VA

Dimensions and mass 215W×80H×320D mm (8.46"W×3.15"H×12.6"D) (excluding

protrusions), approx. 3.0 kg (105.8 oz.)

NOTE

･ The temperature correction function or the temperature conversion function is

selected when the unit is powered on, and only one of these functions can be
used at a time.

･ When using the temperature conversion function, the comparator uses its own

table (High/Low only).

･ Selection of the comparator table with the external interface constitutes a

temperature conversion table selection.

･ Auto ranging is always used when the temperature conversion function is

used.

4

────────────────────────────────────────────────────

1.2 Specifications

────────────────────────────────────────────────────

1

.2.2 Resistance Measurement

Condition 23℃±5℃ (73 F ±9 F), 80% RH or less (no condensation),

After zero adjustment

Pre-heating period 30 minutes
Accuracy assurance period 6 months

Table 1 4-1/2 digit (sampling rate:SLOW)

Range 300 mΩ 3 Ω 30 Ω 300 Ω 3kΩ 30 kΩ 300 kΩ
Resolution 10 μΩ 100 μΩ 1mΩ 10 mΩ 100 mΩ 1 Ω 10 Ω
Measurement

current

100 mA 10 mA 1mA 10 μA

Maximum
applied voltage

30 mV 300 mV 3V 300 mV 3V

Accuracy *

±0.1% rdg

.

±8 dgt.

0.08% rdg. ±3 dgt. ±0.1% rdg.±3dgt.

Temperature
coefficient

(±0.01% rdg.±0.5 dgt.)/℃

Open-terminal
voltage

7.0 Vmax

* If the sampling rate is set to MEDIUM, add 3 dgt to the digit accuracy error.

Table 2 3-1/2 digit (sampling rate:FAST)

Range 300 mΩ 3 Ω 30 Ω 300 Ω 3kΩ
Resolution 100 μΩ 1mΩ 10 mΩ 100 mΩ 1 Ω
Measurement

current

100 mA 10 mA 1mA

Maximum
applied voltage

30 mV 300 mV 3V

Accuracy ±0.2% rdg. ±5 dgt.
Temperature

coefficient

(±0.01% rdg.±0.1 dgt.)/℃

Open-terminal
voltage

7.0 Vmax

5

────────────────────────────────────────────────────

1.2 Specifications

────────────────────────────────────────────────────

1

.2.3 Temperature Measurements

Temperature sensor Platinum resistance element
Dielectric strength 1000 VAC between the temperature sensor sheath and the

voltage terminal(-).

Accuracy assurance range 0.00℃ to 40.00℃
Resolution 0.01℃
Accuracy ±0.5℃
Temperature coefficient ±0.02×(t-23)℃

t : environment temperature where the 3227 is located (℃).

1

.2.4 Temperature Correction Function

Temperature correction range 0.00℃ to 40.00℃ (32 F to 104 F)
Standard temperature range -10.0℃ to 99.9℃ (14 F to 212 F)
Resistance temperature coefficient

range

-9999 ppm to 9999 ppm

Accuracy In the temperature correction, add the value obtained by the

expression below to the accuracy of the resistance measurement

.

±0.5α×100

(%)

1+α((t

0.5) - t

0

)

t: Environment temperature
t

0

: Standard temperature

α: Resistance temperature coefficient

0.5: Temperature measurement accuracy

6

────────────────────────────────────────────────────

1.3 Measurements and Working Systems

────────────────────────────────────────────────────

1

.3.1 4-terminal Measurements

r

2

r

4

r

3

r

1

I

Ohmmete

r

Resistance R

0

Voltmeter

Constant current sourc

e

E

0

E

Measurement Using the 4-terminal Method

1

.3 Measurements and Working Systems

Regular 2-terminal measurement measures even the value which includes the
resistance of the measurement leads or the terminal area. Particularly, when
measuring the low resistance, it is necessary to measure the value without
this resistance value. 4-terminal measurement is able to measure that value.

4-terminal measurement and 2-terminal measurement are explained as
follows. In the figure below, there is very big input impedance in the
voltmeter, and all of the current I flows to the measured resistance R

0

. The r

1

to r

4

means the resistance of the measurement leads or the contact resistance

of the terminal area.

All of the current I flows to the measured resistance R

0

. Therefore, the

voltage drop of r

3

and r

4

become 0, and voltage E and the voltage drop E

0

of

each end of the measured resistance R

0

become equal. Accordingly, the

resistance measurement without influence of r

1

to r

4

becomes possible.

7

────────────────────────────────────────────────────

1.3 Measurements and Working Systems

────────────────────────────────────────────────────

r

2

r

1

I

Ohmmete

r

Resistance R

0

Constant current sourc

e

E

Voltmeter

Measurement Using the 2-terminal Method

1

.3.2 Temperature Probe

Shield cabl

e

Platinum film resisto

r

322

7

The Internal Circuit of the Temperature Probe

The current I flows to the measured resistance R

0

and the wiring resistance r

1

and r

2

. Therefore, the measuring voltage E can be obtained by E=I(r

1

+R

0

+r

2

),

and it would include the wiring resistance r

1

and r

2

.

The 9188 TEMPERATURE PROBE makes temperature measurement and the
temperature correction function easy. In this section, explain the principle of
them.
See Section 3.4.2, "Temperature Correction and Temperature Measurement",
for connecting the temperature probe.

(1) Temperature measurement

The internal circuit of the temperature probe is as follows.

The temperature probe uses the platinum film resistor which is changeable
according to the temperature, as the temperature sensor. This probe displays
the resistance value of that register, detected by the 3227, after converting it
to the temperature using the CPU.

8

────────────────────────────────────────────────────

1.3 Measurements and Working Systems

────────────────────────────────────────────────────

(2) Temperature Correction Function

The temperature correction function displays the optional temperature
coefficient resistance value after converting to the resistance value of the
optional temperature. The resistance depends on the ambient temperature,
and it is of little use to measure the resistance while ignoring this
temperature dependence.

In the following expression, the resistance value R

t

and R

t0

corresponds to the

resistance value of t ℃ and the measured subjects of t

0

℃ (resistance

temperature coefficient in t

0

℃ : αt

0

)

R

t

＝ R

t0

× {1＋α

t0

× (t−t

0

)}

The 3227 obtains the correctional resistance value (R

t0

) from calculating the
temperature measured by the temperature probe (t), the resistance value of
the measured subjects (R

t

), the standard temperature (t

0

) and temperature

coefficient (α

t0

) by CPU.
For example, the resistance value of the copper wire that will be 100Ω under
30℃ would be followingly under 20℃.

R

t

R

t0

＝

{1＋α

t0

× (t−t

0

)}

100

＝

{１＋(3930×10

−6

)×(30−20)}

＝96.22

See Section 5.3, "Setting the Temperature Correction" and Section 5.4,
"Executing the Temperature Correction", for how to set and execute the
temperature correction. Also see "Reference Material" at the end of this
chapter.

(3) Temperature conversion function

The temperature conversion function uses the temperature dependence of the
resistance to convert measured resistance values to temperature values and
display them.

According to JIS C4004, the temperature rise can be derived by the resistive
method as follows:

r

t

Δt=

r

0

(T ＋ t

0

) − (T ＋ t)

r

0

: coil resistance under cold conditions

r

t

: present coil resistance

t

0

: ambient temperature when measuring coil resistance under cold

conditions
t: present ambient temperature
T: constant (copper: 235, aluminum: 230)

9

────────────────────────────────────────────────────

1.3 Measurements and Working Systems

────────────────────────────────────────────────────

NOTE

For example, for a copper conductor, if when the initial temperature t

0

is 20℃

the resistance value r

0

is 200 mΩ, and the present ambient temperature is 25

℃ and the measured resistance value r

t

is 210 mΩ, then the temperature rise

is given as follows:

r

t

Δt=

r

0

(T ＋ t

0

) − (T ＋ t)

210×10

-3

=

(200×10

-3

)×(235 + 20) - (235 + 25)

= 7.75[℃]

As a result, the present temperature of the resistance, t

r

can be found as

follows:

t

r

=t

0

+ Δt = 20 + 7.75 = 27.75℃

When the measured object is not copper or aluminum, from the expression
shown for the temperature correction and the above expression, if the
temperature coefficient is α

t0

, the constant T can be found from the following

expression:

1

T=

-t

0

α

r0

For example, since the temperature coefficient of copper at 20℃ is 3930 ppm,
the constant T at this time is given by

1

T=

- 20 = 234.5,

3930×10

-6

and is substantially the same as the constant 235 laid down by the JIS
standard.

Note that the temperature probe is only designed to measure ambient air
temperature, and it is impossible to measure the surface temperature.
If the temperature probe is to be used in the measurement, make sure that
the 3227 and the temperature probe are thoroughly warmed up before the
measurement. The temperature probe and the device to be measured should
be placed close together during the warm-up, so that both will be as close to
the same temperature as possible during the measurement.

10

────────────────────────────────────────────────────

1.3 Measurements and Working Systems

────────────────────────────────────────────────────

1

.3.3 Measurement Value Display

S

4 Digit Display

F

3 Digit Display

M

REF

%

(1) Measurement value display

Resistance measurement mode
Resistance value display

Display the resistance value of 4

digit (MEDIUM, SLOW) and 3 digit

(FAST) by the sampling rate.

Deviation display
Display the deviation (see the expression below), when comparing with

comparison of the standard value/range.

Resistance measurement value

Deviation ＝

Standard value

See Section 1.3.4, "Comparator Function", for the comparator.

Temperature measurement mode

11

────────────────────────────────────────────────────

1.3 Measurements and Working Systems

────────────────────────────────────────────────────

AUTO

TC

M

Over Flow Display

M

NG Display

S

HOLD

Invalid Data Display

NOTE

Temperature conversion mode
When the temperature conversion function is selected at power on, when the
TC indication on the display is on continuously the converted temperature
value is displayed. When it is blinking, the temperature difference (Δt) is
displayed.

(2) The other display

When the measurement value exceeds the measuring range (30000 count), the
over flow (OF) display is indicated. However, while using the temperature
correction function, this display is indicated when the measuring range
exceeds 99999 count.

When the constant current in the source of current (SOURCE) has any error,
NG display is indicated.

・When the measured resistance value is too big, compared with the measuring

range.
Example:

・When intended to measure 300Ω in the 300mΩ range.
・When the lead wire has been ruptured.
・When the different connection has done among 4-terminals.
・When the leads has opened.

When no measurement has done after turning on the power supply, the
invalid data display is indicated.

An "NG" result is always detected even when not carrying out measurement.
Thus even in the HOLD state, if there is a constant current fault, "NG" on the
display lights with displaying the measurement value being held.

12

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1.3 Measurements and Working Systems

────────────────────────────────────────────────────

1

.3.4 Comparator Function

NOTE

NOTE

Setting limit Display

Resistace measurement

High limit value

HIGH

0 to 99999

Low limit value

LOW

0 to 99999

Temperature

High limit value

HIGH

-999.9 to 999.9℃

Low limit value

LOW

-999.9 to 999.9℃

Setting limit Display

Standard value

REF

0 to 99999

Range

%

0.00 to 99.99%

There are 15 comparator setting tables in the 3227, and the different contents
are able to set to each table.
See Section 5.1, "Setting the Comparator" and Section 5.2, "Executing the
Comparator", for how to set and execute the comparator. See Chapter 6,
"External Control Terminals", for the external control terminals.

The comparator is valid only in the resistance measurement mode, and unable
to use in the temperature measurement mode.
The comparator and the auto range should be used separately.
While displaying the converted temperature, the 3227 has only one
comparator setting table. The comparator tables for normal resistance
measurement cannot be used. In this case reference value/range comparisons
also cannot be executed.

(1) Executing the comparator

The result of the comparator is displayed as follows.
Displayed value > High limit value

High limit value ≧ Displayed value ≧ Low limit value
Low limit value > Displayed value

The result of the comparator is able to output to the external control terminal.

In the over range and the NG states, the comparator result is HIGH.

(2) Comparison method of the comparator

Comparison according to high limit value/low limit value

Comparison according to standard value/range

Comparison value
High limit value = standard value + (｜standard value｜×range ÷ 100)
Low limit value = standard value - (｜standard value｜×range ÷ 100)

13

────────────────────────────────────────────────────

1.3 Measurements and Working Systems

────────────────────────────────────────────────────

NOTE

Type Constituents [%]

Density (×10

3

)

[kg/m

3

]

Conductivity

Temperature
coefficient of

resistance (20℃

)

[ppm]

Annealed copper

wire

Cu ＞ 99.9 8.89 1.00 to 1.02 3810 to 3970

Hard drawn coppe

r

wire

Cu ＞ 99.9 8.89 0.96 to 0.98 3770 to 3850

Cadmium-copper

alloy wire

Cd 0.7 to 1.2 8.94 0.85 to 0.88 3340 to 3460

Silver-copper alloy

wire

Ag 0.03 to 0.1 8.89 0.96 to 0.98 3930

Chromium copper Cr 0.4 to 0.8 0.89

0.40 to 0.50

0.80 to 0.85

20
30

Corson alloy wire

Ni 2.5 to 4.0
Si 0.5 to 1.0

0.25 to 0.45 980 to 1770

Annealed aluminum

wire

AI ＞ 99.5 2.7 0.63 to 0.64 42

Hard drawn

aluminum wire

AI ＞ 99.5 2.7 0.60 to 0.62 40

Aldrey wire

Si 0.4 to 0.6

Mg 0.4 to 0.5

Parts containing A

l

0.50 to 0.55 36

･ When comparing by the standard value/range, the measurement value is

displayed as the deviation.

･ Always set the high limit value bigger than the low limit value.
･ Ignoring the measurement range, perform the comparison only by the

measurement count value.

･ The digit which is not indicated on the display is dealt as 0, when performing

the comparison.

(3) Buzzer mode

HL The buzzer would sound in case of HIGH or LOW.
IN The buzzer would sound in case of IN.
OFF No buzzer would sound.

(4) External control terminal mode

AUTO The comparator result is output with each samples.
EXT The comparator result is output by the MANU

―――――――

terminal state in the

external control terminal.

Reference Material

14

────────────────────────────────────────────────────

1.3 Measurements and Working Systems

────────────────────────────────────────────────────

Diameter [mm]

Annealed copper

wire

Tin-plated annealed

copper wire

Hard drawn coppe

r

wire

0.10 to 0.26

(excluding 0.26

)

0.98 0.93

0.26 to 0.50

(excluding 0.50

)

0.993 0.94 0.96

0.50 to 2.00

(excluding 2.00

)

1.00 0.96 0.96

2.00 to 8.00

(excluding 8.00

)

1.00 0.97 0.97

α

Ct

=

1

α

20

× C

+(t 20

)

1

α

20

=

1

0.00393 × 0.9

3

+ (20 20

)

1

≒ 3650 (ppm

)

(1) Properties of metal and alloy conductive materials

(2) Conductivity of copper wire

The temperature coefficient changes in relation to temperature and
conductivity. Assume the temperature coefficient is α

20

at 20℃ and that the

temperature coefficient is α

Ct

at t (℃) with a conductivity of C. Then Ct at

around room temperature is represented as follows:

The temperature coefficient of international standard annealed copper is 3930
ppm at 20℃. For tin-plated annealed copper wire (not less than 0.10 but
below 0.26 in diameter), the temperature coefficient α

20

at 20℃ can be

calculated using the following formula:

15

────────────────────────────────────────────────────

2.1 Front Panel

────────────────────────────────────────────────────

AUTO UP DOWN

GP-IB ADRS

ENTER

CLEAR

TC

SHIFT

COMP

LOCK

TEMP

HOLD

0 ADJ

SAMP

50/60Hz

SET

SET

INPUT

SENSE SOURCE

H

L

Rx

▼

▼

12345678910111213

14

1234567

8

91011121314

Chapter

2

Part Name

s

2

.1 Front Panel

Display
AUTO key
UP key
DOWN key
Cusor keys
ENTER key
TEMP key (Temperature measurement (zero adjustment) )
HOLD key (Sampling rate setting)
COMP key (Comparator setting)
LOCK key (Power supply frequency setting)
TC key (Temperature correction setting)
SHIFT key
Input terminals
Handle

16

────────────────────────────────────────────────────

2.2 Rear Panel

────────────────────────────────────────────────────

1516171819

20

1

51617181920

2

.2 Rear Panel

Power supply inlet
POWER switch
Digital I/O connector
Temperature probe connector
External control terminal block
Option slot

17

────────────────────────────────────────────────────

2.3 Displays

────────────────────────────────────────────────────

REMOTE LOCK SHIFT

FMS

AUTO

HOLD

k

HIGH

REF

LOW

%

ppm

COMP

TC

High limit value Standard value Setting value Range Resistance coefficien

t

Standard temperature Low limit value

Sampling rat

e

Auto rang

e

Hold stat

e

Comparato

r

Temperatur

e

correctio

n

Measurement unit

Remote state Key shift state Comparator resu

lt

Measurement value Key lock state NG

2

.3 Displays

18

────────────────────────────────────────────────────

2.4 Accessory and Options

────────────────────────────────────────────────────

Sensor par

t

Cabl

e

Connecto

r

HIOKI 9188

MADE IN JAPAN

GP-IB connecto

r

9588 GP-IB INTERFACE

GP-IB

MADE IN JAPAN

9589 PRINTER INTERFACE

MADE IN JAPAN

Printer connecto

r

2

.4 Accessory and Options

Accessory
9188 TEMPERATURE PROBE

Options
9588 GP-IB INTERFACE

9589 PRINTER INTERFACE