TD-1002b

INSTRUCTION MANUAL

Temperature Sensor
Instruction Manual

OKAZAKI MANUFACTURING COMPANY

Instruction Manual

OKAZAKI MANUFACTURING COMPANY
1-3 GOKODORI 3-CHOME, CHUOU-KU, KOBE 651-0087, JAPAN
PHONE : 078-251-8200

FAX : 078-251-8210

http://www.okazaki-mfg.com/index.html
E-mail : sales@okazaki-mfg.com
Note : 1) All provisions are subject to change without any notice.
2) This manual is prepared with the greatest possible care, but if any problems,
please do not hesitate to contact us.

OKAZAKI MANUFACTURING COMPANY

TD-1002b

INSTRUCTION MANUAL

Index
CHAPTER 1 BEFORE TO USING

1

1.1

ATTENTION TO SAFETY ··························································································· 2

1.2

WHEN BREAK DOWN ······························································································· 5

CHAPTER 2 INTRODUCTION
CHAPTER 3 TEMPERATURE SENSOR OVERVIEW

6
7

3.1

TYPES OF TEMPERATURE SENSORS ······································································· 7

3.2

MEASUREMENT PRINCIPLE OF THERMOCOUPLE ····················································· 7

3.3

TYPES OF THERMOCOUPLE ···················································································· 8

3.4

MEASUREMENT PRINCIPLE OF RESISTANCE THERMOMETER SENSOR ····················· 8

3.5

TYPES OF RESISTANCE THERMOMETER SENSOR ··················································· 10

CHAPTER 4 PRIOR TO INSTALLATION

11

4.1

TO CHECK ITEMS AFTER UNPACKING······································································ 11

4.2

PRECAUTIONS FOR STORING THE TEMPERATURE SENSOR ···································· 11

4.3

MEASUREMENT OF CONTINUITY············································································· 11

4.4

MEASUREMENT OF INSULATION RESISTANCE ························································· 12

4.5

PRECAUTIONS FOR DIELECTRIC STRENGTH TEST ·················································· 13

CHAPTER 5 INSTALLATION

13

5.1

INSTALLATION PLACE ····························································································· 14

5.2

ACCURATE TEMPERATURE MEASUREMENT ···························································· 14

5.3

PRECAUTIONS FOR CONNECTING THE EXTERNAL WIRING ······································ 15

CHAPTER 6 SAFETY USE

18

6.1

MAINTENANCE ······································································································· 18

6.2

MAINTENANCE AND INSPECTION ············································································ 18

6.3

PERIODIC OF INSPECTION TEMPERATURE SENSOR ················································ 20

CHAPTER 7 TROUBLESHOOTING

23

7.1

IDENTIFYING PROBLEMS ························································································ 23

7.2

TROUBLESHOOTING FOR THERMOCOUPES ···························································· 23

7.3

TROUBLESHOOTING FOR RESISTANCE THERMOMETER SENSORS ·························· 23

CHAPTER 8 BASIC SPECIFICATIONS AND STRUCTURE OF TEMPERATURE SENSORS

25

8.1

PROTECTION TUBE TYPE TEMPERATURE SENSORS················································ 25

8.2

SHEATHED TEMPERATURE SENSOR ······································································· 26

8.3

EXPLOSION-PROOF TEMPERATURE SENSOR ·························································· 27

8.4

LEAD WIRE TYPE TEMPERATURE SENSOR ······························································ 29

CHAPTER 9 REFERENCE MATERIAL

30

9.1

THERMOCOUPLE REFERENCE THERMO-ELECTROMOTIVE FORCE TABLE ················ 30

9.2

COLOR CODES FOR COMPENSATING CABLES························································· 33

9.3

TOLERANCE OF THERMOCOUPLES········································································· 33

9.4

RESISTANCE THERMOMETER SENSOR REFERENCE RESISTANCE VALUE TABLE ······ 35

9.5

RESISTANCE THERMOMETER SENSOR TOLERANCES ············································· 35

9.6

MAJOR STANDARDS LIST························································································ 36

CHAPTER 10 CONTACT ADRESS AND PHONE NUMBERS IN CASE OF TROUBLEOKAZAKI MANUFACTURING COMPANY

371

TD-1002b

INSTRUCTION MANUAL

CHAPTER 1 BEFORE TO USING
1.1

Attention to safety
Before using this product, carefully read both this " Attention to Safety " and the " Instruction Manual".
Only use the product after having well understood the proper method of operation. The safety warnings
shown below are to prevent harm or injury to yourself and the people near you when operating thetemperature sensor. The two labels below describe what will happen in the unlikely
event of mistake being made during handling or operation of the temperature.

WARNINGCAUTION

If this device is improperly used,
If this device is improperly used, people
people may be severely injured or
may suffer light to medium injuries orkilled.
material damage may occur.
Even items bearing a "Caution" label may, under certain conditions, lead to serious injury. Always
observe safety procedures.
The terms "serious injury", "light injury", and "material damage" mentioned above have the following
meanings.
Meaning
Term
Long-term symptoms resulting as a result of loss of eyesight, injuries, burns (high &Serious
low temperature), electric shock, broken bones. Injuries will require a long period in
Injuryhospital followed by repeated hospital visits.
Injuries, burns (high & low temperature) or injuries from electric shocks which do notLightrequire a long hospital stay or repeated hospital visit.
InjuryMaterial
Direct and indirect losses associated with inventory loss, and damage to plant anddamageequipment.

INSTALLATIONWARNING

Do not connect lead cable of temperature sensors directly topower supply terminals.

Lead cable ( compensating lead cable or extension lead cable) of temperature sensors must beconnected to terminal of receiving instruments. If connected by mistake to power supply, temperature
becomes high that may cause a fire or an explosion.
WARNING

Do not handled temperature sensor roughly.

There are heavy temperature sensors because of their constructions. If they drop from installation point,
it might cause damage to person. Resistance thermometers which have very fine platinum wires are
extremely delicate, therefore, temperature measurement error may be caused by damage. For
temperature sensors with ceramic insulators or protection tubes, special attention of these sensors are
required because of their brittleness.
WARNING

Do not use temperature sensors for hazardous locations insurrounding where temperature is over 60°C.

Temperature sensors for hazardous location are approved provided that they are used in surrounding
where temperature is below 60°C. Please specify the surrounding temperature in location in order tomake it safe.

2

OKAZAKI MANUFACTURING COMPANY

TD-1002b

INSTRUCTION MANUALWARNING

Make sure of closing a cover of terminal head after wiring.

After wiring , if “O” ring is supplied, then make sure “O” ring is installed properly in cover of terminal
head before installing the cover. This will prevent dust or rain entering terminal head. This is specially
important for explosion proof terminal head, close the cover with a rated jig. For general type terminal
head, use a screw driver shown below. For closing, turn the cover clockwise by hand and then tighten it
1/6~1/4 clockwise with jigs. The temperature sensors nay not display correct temperature due topresence of dust or rain.
CAUTION

Make sure of mounting with screws or flanges.

Installation of temperature sensors will be done with screws or flanges. In case of screwing, apply
sealing tape or sealing agent for tapered thread, and O-ring gasket for parallel thread, and then tighten
with spanner. For flange connection, use
specified gasket and tighten all bolts equally.
If air tightness is required, carry out the air
tightness inspection after installation. For
screwing sensor into thermowell, be sure totighten at job site.

CAUTION

Please note bending portion and bending radius of metal
sheathed mineral insulated type temperature sensors.

Material can be bent to a minimum radius of 2 times of sheath diameter, any bending tighter than that,will fracture the sheath. On bending at job site, bend to a radius of around 5 times of sheath diameter.
However, do not bend near the sleeve. The conductor wire inside of the sheath is pulled by bend and it
may be disconnected near the connecting part inside the sleeve.
For metal sheathed mineral insulated type resistance thermometers, do not bend 70mm length from thetip, where resistance element is installed.

For metal sheathed mineral insulated type thermocouples, do not bend 5mm (φD ≦ 3.2) length from thetip, where thermocouple wire is installed. And, do not apply any external force that may cause
deformation such as dent on that surface. By thermal effect at the time of tip processing, the crack may
occur, and also there is a possibility that the element wire is disconnected depending on the bending
direction.

OKAZAKI MANUFACTURING COMPANY

3

TD-1002b

INSTRUCTION MANUALWARNING

Please consider carefully the bending position andbending radius for a lead wire type temperature sensor.

As for circular part above, when performing bending in the close vicinity of metal tip containing atemperature-sensitive element, do not perform any action while applying excessive force to thetemperature sensor, such as pulling the lead wire. It may cause defects in measuring temperature. In
cause defects in measuring temperature as well.

CAUTION

Do not expose terminals and connection portion with lead
cables at temperature over 80°C.

Incase of connection portion between temperature sensors and lead cables is exposed to hightemperature, insulation resistance may become poor or measuring error may be caused. therefore,
unless stated application for high-temperature, the surrounding temperature of both terminals andconnection with lead cables should be below 80°C.
CAUTION

Make sure of polarity on connecting to terminals.

On connecting lead cables to terminals of temperature sensors, please make sure of the polarity. In caseof wrong connection, it is impossible to measure the correct temperature due to big measuring error
caused by wrong connection. Special attention to color of compensating cable is required because thecolor is different per applicable standard.

MAINTENANCE AND INSPECTIONWARNING

Do not open the cover of the terminal head in operation,
located hazardous area.

It’s possible to make ignition that is very dangerous.
WARNING

Do not use insulation resistance tester when plant operated.

When the plant is operated, it might be danger of leakage of explosive gases. Therefore, for checking
the performance of temperature sensors, please do not use insulation resistance tester. There is apossibility in causing spark on using the insulation resistance tester which applies high-voltage. And it
might be ignition factor of explosive gases.
WARNING

Do not disassemble or repair at site temperature sensors to
be located hazardous area.

Flame proof temperature sensors which are located in hazardous area have approved construction bynational institution. Therefore, it is not approved that the sensors are disassembled or repaired at otherthan approved factory because of its safety. Please be sure to send back to manufacturer to repair. Do
not disassemble or repair at site.
4

OKAZAKI MANUFACTURING COMPANY

TD-1002b

INSTRUCTION MANUALWARNING

Please check shutdown, ordinary temperature andpressure on maintenance, inspection and replacement.

There are many cases of high temperature and pressure in the location where temperature sensors are
installed. Therefore, it is very dangerous to start inspection in operating or just after shutdown. Pleaseconfirm the shutdown, and also confirm if the temperature and pressure become normally, and thenstart inspection and replacement works.
CAUTION

Do not touch sensing probe of temperature sensors.

Temperature sensors are used at high temperature and low temperature. Therefore, the sensor pulled
out from installation point may be still hot or cold. Please note that in case touching with bare hand, it
might be burnt or frostbitten. Do not touch until the temperature of sensors is close to room
temperature.
CAUTION

Do not pull by force lead cable of lead cable type temperature
sensors.

If pulled by force the lead cable of lead cable type temperature sensors, the wire might be broken atconnection point. For the lead cable protected with flexible tube, the tube might get out of place atconnection.
CAUTION

Do not use temperature sensors as footing.

Do not use the installed temperature sensors as footing when inspection works and so on. The
temperature sensors have not any mechanical strength, therefore, they might be damaged or cause awire break.

STORAGECAUTIONStore temperature sensors in dry and clean place.

Temperature sensors should be stored in a dry and in a clean place. The storage at in a high humidity
place may cause low insulation resistance.

DISPOSALCAUTION

Scrap temperature sensors as industrial waste.

In case of disposal of temperature sensors, handle as industrial waste. If it is difficult to dispose off, ask
industrial waste treatment traders approved by prefectural governor.
1.2

WHEN BREAK DOWN
Please contact the following post when trouble is caused in the equipment.
Manufacturing and sales : OKAZAKI MANUFACTURING COMPANY
Head office:1-3 GOKODORI 3-CHOME, CHUO-KU, KOBE 651-0087, JAPAN
PHONE : 078-251-8200

Tokyo branch:18-3, KOAMI-CHO, NIHONBASHI,CHUO-KU, TOKYO 103-0016
PHONE : 03-5641-0200

Head factory

FAX : 03-5641-9100: 1-2-4, MUROTANI, NISHI-KU, KOBE 651-2241, JAPAN
PHONE : 078-991-5567

E-mail

FAX : 078-251-8210

FAX : 078-991-6800: sales@okazaki-mfg.com

OKAZAKI MANUFACTURING COMPANY

5

TD-1002b

INSTRUCTION MANUAL

CHAPTER 2 INTRODUCTION
Thank you for purchasing our temperature sensor.
Okazaki temperature sensors are manufactured and tested by experienced technicians under an ISO
9001 quality control system. Following the recommendations in this manual can help obtain maximum
life and dependability.
If you are using a temperature sensor for the first time, we suggest you read Chapter 3"TEMPERATURE SENSOR OVERVIEW”. Chapter 3 briefly describes the functional principles oftemperature sensors and provides basic usage information.
“CHAPTER 4 PRIOR TO INSTALLATION” and Chapter 5 "INSTALLATION” offer detailed
technical instructions.
Temperature sensors are instruments and require careful handling until they have been installed.

6

OKAZAKI MANUFACTURING COMPANYINSTRUCTION MANUAL

TD-1002b

CHAPTER 3 TEMPERATURE SENSOR OVERVIEW
3.1

Types of Temperature Sensors
Temperature sensors used for industrial purposes are generally classified into three groups;
thermocouples, resistance thermometer sensors (RTS), and radiation thermometers.
We will discuss in detail thermocouples and resistance thermometer sensors which are our major
products. Thermocouple and resistance thermometer outputs can be transmitted as electrical signals,
unlike mercury thermometers or bi-metal type thermometers. Thermocouples can be used to measuretemperatures over a wide range. Resistance thermometers can measure temperatures with highaccuracy.
Since the radiation thermometer is a non-contact measurement type, it is used for temperature control inapplications where temperatures cannot be measured by contact: for example, surface temperature
control of the steel plates in a continuous steel manufacturing line and temperature control offilm-shaped products. The electrical signals from temperature sensors are used to control many different
operations in a variety of industries. The steel, petrochemical and energy related industries are thelargest users of temperature sensors. Many of these sensors are supplied with a temperature transmitter
installed which converts the electrical output of a thermocouple or resistance thermometer sensor into a
4-20mA DC signal.

3.2

Measurement Principle of Thermocouple
Thermocouple theory is based on the circuit to the Fig.1. A current will flow if two dissimilar metals arejoined at each end with T1 and T2 being two different temperatures. In actual use: A would be themeasuring junction and connection B would go to a voltage
measuring instrument. The output is a very small voltage, known
as an electromotive force.
Chromel-Alumel is the most well-known combination of two
Fig. 1 Principle of Thermocouple
kinds of alloy wires. It used to be called a CA thermocouple. It is
now known as type “K”. The contact on the temperature
measuring side is called a measuring junction or a hot junction, and the other side a reference junction in
the Fig.2. Generally, it measures the electromotive force caused by the temperature difference from themeasuring side, while keeping the reference junction at 0°C. The table which represents the relationshipbetween the temperature and electromotive force is called astandard electromotive force (EMF) table. This table isreferenced by many internationally recognized standards suchas JIS, IEC, ISA, etc. In the past, there were some differencesin the standard EMF’s recognized by the different countries.
However, most countries are now using the same tables.
Chapter 8 "REFERENCE MATERIAL" lists the tables of thestandard EMF (JIS, IEC & ASTM).
Fig. 2 Measuring Circuit

OKAZAKI MANUFACTURING COMPANY

7

TD-1002b
3.3

INSTRUCTION MANUAL

Types of Thermocouple
The thermocouples mainly used for industrial purposes have been standardized. In Japan, they havebeen stipulated in the JIS C 1602. Table 1 lists their types and features.
Table 1
Type
B
R
S
C

Composition+

Pt-30Rh−+−+−

Pt-6RhPt-13Rh
Pt
Pt-10Rh
Pt

Major Feature
Suitable for the use in oxidizing or inert gas atmosphere from 870 to 1700°C.
Compensating cable not required because of small EMF at room temperature.
Because the thermo-electromotive force at the normal temperature is small, copper
can be used for the material of the compensating wire.
Suitable for the use in oxidizing or inert gas atmosphere from 0 to
1480°C.Platinum Thermocouple not to be directly inserted into a metallic
protection tube. Therefore, longevity is extremely short at 1000°C or more though
R thermo-couple of the NCF600 sheath type exists as a product.

+

W-5Re

Available until 2200℃ in a vacuum, in an inert gas or in dry hydrogen. When it is−

W-26Re+Ni-14.2Cr-1.4Si−

Ni-4.4Si-0.15Mg+

Ni-10Cr−

Ni-2Al-2Mn-1Si+−

Ni-10Cr
Cu-45Ni+

99.5Fe−Cu-45Ni+

Cu−

Cu-45Ni

N

K

E

J

T

3.4

Types of Thermocouples

in the high temperature air of ≧500℃ , oxidize in short time. (Added to JIS
C1602:2015、IEC 60584-1:2013)
Developed to remove weak points of K Thermocouple. Si added to both thepositive and negative wires and calibration drift is reduced. Cr added to positive
wire. Oxidation resistance at high temperature improved and short range orderingfeatures reduced.
Suitable for the use in oxidizing or inert gas atmosphere from -200 to 1260°C.
Not suitable for the use in reducing gas atmosphere. Depending on theconditions, Green rot corrosion and extreme EMF drop caused in a very short time.
Not suitable for the use in sulfuric atmosphere because of high Ni contents.
When the insertion length changes when calibrating and using it again because
there is an increase of EMF by SRO when using it in the temperature span from
250°C to 600°C, it is necessary to note it.
Suitable for the use in oxidizing or inert gas atmosphere from -200 to 900°C, not in
reducing gas atmosphere. Can be used for lower temperature than 0°C.
Suitable for the use in vacuum and oxidizing, reducing and inert gas atmosphere.
When used at higher temperature than 540°C, thick wire required to be used,because Fe oxidation of the positive occurs rapidly. Cannot be used at lower
temperature than 0°C.
Suitable for the use in oxidizing, reducing and inert gas atmosphere from -200 to
370°C. Can be used at lower temperature than 0°C. At the high limit temperature,
Cu is oxidized.

Measurement Principle of Resistance Thermometer sensor
Resistance thermometer sensors (RTS), make use of thecharacteristic that the electrical resistance values of themetals, semiconductors, etc. Change depending on thetemperature. Some of the metals used include platinum,
nickel, and copper. There metals all have the common
characteristic that as the temperature rises, the resistancevalue increases.
The most widely used resistance thermometer sensors forindustrial purposes are platinum resistance thermometer
sensors which have a wide working temperature range andlarge resistance temperature coefficient. Therrmistors use asemiconductor for resistance change as a function of

8

Fig. 3 Temperature Characteristic of
Platinum Wire

OKAZAKI MANUFACTURING COMPANY

TD-1002b

INSTRUCTION MANUAL

temperature. There are usually used in electronic consumer products and normally not in industrial
applications.
Resistance measurement requires either a bridge, or the potential method which replaces the resistancechange with a voltage change, using a constant current source.

Fig.4 Connecting configuration

There are three common methods to connect the conductors for resistance measurement. As sh
own in the connection diagrams, they have the following features, sequentially from the top.
2-wire configuration : This configurations allows no compensation of conductor resistance and canprovide good accuracy only with short conductor leads. This type is not usuallyused except for high resistance RTS’s.
3-wire configuration : This type of connection is used to eliminate the effect of conductor resistance.
Care should be taken for long-distance transmission because variations in theresistance of conductors can have an effect on accuracy. This type of
connection is most widely used in industrial applications.
4-wire configuration : This type of connection is used for high-accuracy measurement and standards
because it is not affected by conductor resistance. Generally, a constant current
is applied and the resistance value is measured by a potential difference.
In addition, in JIS C 1604 (1997 ed.), the symbol A specified as Red and symbol B specified as White.
In JIS C 1604 (2013 ed.) and IEC standards, symbol A specified as White and symbol B specified as
Red.
In order to reduce the uncertainty at the time of inspection in our company, it has decided to identify
clearly the current terminal "b". In our standards, limited to 3-wire type, the symbols shall specify as "A,B, b", instead of "A, B, B"

OKAZAKI MANUFACTURING COMPANY

9

TD-1002b
3.5

INSTRUCTION MANUAL

Types of Resistance Thermometer sensor
The resistance thermometer sensors most widely used for industrial purposes are platinum resistancethermometer sensors. They are stipulated by the JIS C 1604 in Japan. There are currently two types; one is
Pt100 which conforms to the international standard, and the other is JPt 100 which is the Japanesestandard. They are not interchangeable because the ratio of resistance values at 100 °C and 0 °C (R100/
R0) differ.
Table 2 Types of Platinum Resistance Thermometer sensors
Type

R00/R0Pt100

1.3851

JPt1001.3916

Many of the resistance thermometer sensors in other countries conform to the IEC Standard. In Britain
and Germany, their standards are exactly the same as the IEC Pub 60751 .
Abbreviations :JIS:
Japanese Industrial Standards
IEC:International Electrotechnical Commission
ASTM:
American Society for Testing and Materials

10

OKAZAKI MANUFACTURING COMPANYINSTRUCTION MANUAL

TD-1002b

CHAPTER 4 PRIOR TO INSTALLATION
4.1

To Check Items after Unpacking
Our temperature sensors have been produced under quality control procedure and shipped after in-houseinspection.
The package shipped contains the following:(1) In the package: Temperature sensors
Accessories
Inspection report(2) Pasted outside the package : List of items (Packing List)
Check the package for its contents to be sure that they match the list of items. Also, check the quantityand appearance of each item for shortage and damage. Since the type of temperature sensor is indicatedon the product name plate, confirm that the temperature sensor is the same as the one you have ordered.

4.2

Precautions for Storing the Temperature Sensor
When you do not immediately use the temperature sensor and want to store it for some time, observe thefollowing:(1) Check for continuity and insulation resistance before storing. As for the checking method, follow the
instruction for checking continuity (4.3) and that of insulation resistance (4.4). (This does not apply togrounded junction thermocouples, wire and insulator type temperature sensors without protection tube orbare wire elements).
(2) Avoid any dusty or humid places where insulation resistance is likely to be reduced. Store thetemperature sensor in an indoor dry area.
(3) When storing temperature sensors for a long time, put into a terminal box a water-proof sealed
polyethylene bag together with silica-gel. Silica gel should be replaced annually.
(4) Do not apply mechanical vibration or shock.

4.3

Measurement of Continuity
With an ohmmeter, check resistance between the output terminals of the temperature sensor. Set the tester
to the resistance () measurement range. The sensor is basically usable if it has continuity. If the tester
indicates a reasonable resistance value whether it is analog or digital type, the temperature sensor isusually all right. If the tester indicates an infinite value or very high value (several 100kΩ), thetemperature sensor is very likely to have an open circuit. Contact our dealer or office and send the productback. The terminals used for a temperature sensor continuity check are as follow :(1) For the thermocouple
With the compensation lead wires :Between red and whiteWith the terminal box:
Between + and –For more accurate judgment, compare with Table 3 and Table 4

OKAZAKI MANUFACTURING COMPANY

11

TD-1002b

INSTRUCTION MANUAL
Table 3 Resistance Values for Thermocouples(Ω/m at Room Temperature)

Strand
0.32
0.5
0.65
0.8
1.0
1.6
2.3
3.2

Sheath Dia.
0.25
0.5
1.0
1.6
3.2
4.8
6.4
8.0-

N
61
24.2
6.8
3.1
1.8
1.0
-

K
944.3
242.4
60.1
23.5
12.5
5.92
3.0
2.63
1.6
1.03
0.5
0.24
0.12

E
76.3
29.8
15
7.45
3.6
3.31
1.97
1.26
0.6
0.29
0.15

J
40.0
15.6
7.3
3.84
1.8
1.71
1.05
0.67
0.3
0.14
0.07

T
33
12.9
6.3
3.22
1.5
1.43
0.84
0.54
0.25
0.12
0.06

R
1.5
-

Remarks : The data above are reference values for a comparison check only ( not standard values).The
compensation lead wires are omitted because there are too many types to describe.
(2) For the resistance thermometer sensors
With extension lead wires:
Between white, and red and red and red.
With a terminal box:
Between A and B(b), and B and B(b)(4-wire type: Measured between A and A as well)
Table 4 Resistance Values for Resistance Thermometer sensor(Pt 100 Ω) (Reference Values at Room Temperature)
Measuring Spot

Resistance Value

Between A-B or red-white

106〜112Ω

*Between B-B or white-white

0.1〜5Ω

Remarks : * Cannot apply to a sheath outer diameter of 2.3 mm or less.
4.4

Measurement of Insulation ResistanceWith an insulation resistance tester (megger), check between the output pin of the temperature sensor
and its main body or sheath. Depending on the type of temperature sensor and the sheath and protection
tube outside diameters, the applied voltage of the insulation resistance tester must be varied. Applying a
voltage higher than shown in table 5 and 6 may destroy insulation or cause a failure. The following tablelists the rated voltage applicable to the temperature sensor size. It is recommended to use the lowest
voltage available which results in a reading.
Table 5 Rated Voltages Applicable to Temperature Sensor for Routine Test
(JIS C 1602, C 1605-1995: * Company’s standard)Type of Thermocouple/Sheath O.D.
Thermocouple with Protection Tube
φ0.1<=O.D.< φ0.15 *φ0.15<=O.D.< φ0.5 *Mineral Insulated
Thermocouple
φ0.5 <=O.D.< φ2.0
φ2.0 < = O.D.

12

Insulation Resistance /Voltage Applicable
10MΩ/500VDC
1MΩ/3VDC
5MΩ/50VDC
20MΩ/100VDC
100MΩ/500VDC
OKAZAKI MANUFACTURING COMPANY

TD-1002b

INSTRUCTION MANUAL

Table 6 Rated Voltage and Insulation Resistance Values Applicable to Resistance
Thermometer sensor for Routine Test (JIS C 1604-2013)
Type of Resistance Thermometer Sensors/Sheath O.D.
Resistance Thermometer Sensor
with Protection Tube
Sheath O.D. 0.8 <= O.D. <=12.7

Insulation Resistance / Voltage
Applicable
100MΩ/100VDCor 125VDC

The above mentioned values are given at time of shipment
and should apply for receiving inspection. After delivery, insulation
resistance values can decrease due to effects of installation,
or decrease over a long period of time. In most cases, both thermocouples
and resistance thermometer detectors with minimum insulation values in thehundreds of KΩ range would operate without any performance problems.
(Reference – http://www.okazaki-mfg.com/faq/faq-j-tc.html)
However, we would still recommend replacement since these sensors may
be susceptible to electrical noise interference when resistance value
measured is less than 1MΩ.

Fig.5 Measurement of insulation resistance

4.5

Precautions for Dielectric Strength Test
There is a provision of Dielectric Strength Test in JIS for both thermocouple and resistancethermometer sensor that is defined as type test or additional test. The test will not be performed in thedelivery inspection unless otherwise requested. However, the Dielectric Strength Test can be performedby specified voltage upon request by particular customer. The maximum applied voltage to the both
thermocouple and resistance thermometer sensor is AC500V. In the case of performing the test
exceeding it, require caution; the design changes may be necessary.

OKAZAKI MANUFACTURING COMPANY

13

TD-1002b

INSTRUCTION MANUAL

CHAPTER 5 INSTALLATION
Temperature sensors used for industrial purposes are installed in places where temperature
measurement is required for operation of various manufacturing plants. However, they should never be
installed in the following places.
5.1

Installation Place
Temperature sensors used for industrial purposes are installed in places where temperature
measurement is required for operation of various manufacturing plants. However, they should never be
installed in the following places :(1) Where a high temperature heat source is located nearby and the terminal box or a joint (sleeve) has atemperature of 80°C or more. Note that measuring temperature with an explosion-proof temperature
sensor requires the ambient temperature not to exceed 60°C.
(2) Where a high-voltage power source is located and a high voltage is likely to be applied to thetemperature sensor due to an electric leakage.
(3) Where the joint (sleeve) is exposed to the rain, sprinkled water, or excessive moisture when thetemperature sensor is used without a terminal box.
(4) In an area where a worker may step on or mechanically shock the temperature sensor.
In a petrochemical or gas manufacturing plant, the temperature sensor may be installed in the hazardous
location.
In that case, use an explosion-proof temperature sensor whose grade is suitable for that area. There are
two types of explosion-proof temperature sensors; flame-proof type and intrinsic safety explosion-proof
type. As for explosion-proof temperature sensors, refer to Section 8-3.

5.2

Accurate Temperature Measurement
In order to measure the temperature accurately, the temperature sensor should be thermally balanced
against the object measured. To that end, it must be installed so that it is not affected by heat transfer orheat conduction from its surroundings. Observe the following points, depending on the object measured.
(1) Temperature measurement of fluid in a pipe or tank.
If the actual insertion length of the protection tube is short, the temperature
sensor will be thermally affected from the surrounding area and cause anerror. The required insertion length will differ depending on the fluid type,specific gravity, and flow speed. Install the temperature sensor so that theinsertion length will be longer than the values shown in table 4-2. Assume
them as the minimum required values. When installing with an angle tube
to compensate for small diameter piping, place the tube toward the
upstream direction of flow, place it in an elbow area or use a bigger piping
size for the measuring area.
LA: Insertion Length ( Actual Insertion )L: Insertion Length ( Total length )And furthermore, there are cases where the insertion length to be shortened
Fig.6 Actual insertion length
depending on the calculation results with fluid conditions (temperature,pressure and velocity, etc.) and the protection tube specifications (material, insertion length, outside
diameter and thickness, etc.).
In that case, the protection tube may be used by length less than insertion length described in Table-7.

14

OKAZAKI MANUFACTURING COMPANY

TD-1002b

INSTRUCTION MANUAL

Please note that the error by lack of insertion length differ depending on the fluid type or the velocity.
Table-7 Insertion length to recommend

Type of Fluid
LiquidGas

Thermocouple
5 times or longer than thethermowell's outer
diameter
10 times or longer than thethermowell's outer
diameterResistance Thermometer5 times or longer than thethermowell's outer
diameter + resistor length
10 times or longer than thethermowell's outer
diameter + resistor length(2)
Surface temperature
measurement of a solid
Apply the temperature sensor tightly to the surface of the solid you want to measure. To do this, place
the temperature sensor parallel to the object measured for as long as possible to avoid a thermal effectfrom the surroundings. When the ambient temperature is higher than the surface, this can help avoid theeffects of radiant heat. An ideal approach would be to lay the temperature sensor inside a slot or holein the surface of the solid being measured.
(3) Temperature measurement inside a furnace
To accurately measure the temperature of a high-temperature gas, a sufficient insertion length isrequired. Since the wires tend to deteriorate due to atmospheric gases, it is necessary to select a propermaterial for the protection tube or to use a purging gas.
The required insertion length is about 10 to 15 times or longer than the outer diameter of the protection
tube.
5.3

Precautions for Connecting the External Wiring
After installing the temperature sensor in the desired measuringlocation connect external conductors
to send its signal to a receiver. In this case, note that the type of the
conductors used for thermocouple and resistance thermometer sensors
are different.
(1) Mineral Insulated Thermocouple
For the external conductors, use the standard compensation lead wires
recommended for each thermocouple type. Be particularly aware thatuse of the wrong type of compensation lead wires can cause a large
error. The color coding of compensation lead wires differ dependingon the type of the wire and the color regulations specified in various
standard such as JIS, ANSI, IEC, etc. An erroneous connection of +/may also cause a large error. Make sure that the temperature at thejoint is 80°C or less. Since the normal compensation temperature
range of the compensation lead wires is about 100°C, a connection toa high-temperature section causes an unexpected error. Also, makesure that the insulation coating material is sufficient to withstand theFig.7 Terminal layout
working conditions and environment. For normal vinyl coating, theupper limit of the allowable temperature is about 90°C. When the external wiring may be exposed to therain, etc., do not use the conductors with fiber glass insulation coating. If used, moisture or humidity will
reduce insulation resistance and cause an error.
The discernment color of the standard of each country is shown in table 8.
15

OKAZAKI MANUFACTURING COMPANY

TD-1002b

INSTRUCTION MANUAL
Table 8 Compensating cable color code

Thermocouple type

B

R/S

N

K

E

J

T

IEC
60584-3:2007
JIS C 1610:2012

JIS
C 1610-1995
Class 2-

ASTM
E-230-2008(2) Resistance thermometer sensor
Control cables are generally used as the external conductors. For example, if a measurement is donewith a 3-wire connection, each sensor requires 3 wires. In JIS C1604: 2013 edition, the terminal symbol
identifies as White-Red-Red or A-B-B. However, the company since April 2015 regards theidentification color as the main object, it specifies as A-B-b limited to 3-wire type in order to clarify thecurrent terminal “b” at the time of measurement. (For lead wire type, indicating “b” only at the Red side,
but it may differ depending on the conditions.) In case of the sheath length exceeding 700 mm, pleasecheck the current terminal of measurement device and connect to the “b” terminal of our device.
As with the thermocouple compensation lead wires, select the insulation coating material suitable for the
installation environment. When the external wiring may be exposed to rain, etc., do not use theconductors with fiber glass insulation(3) Grounding method
When you install a temperature sensor and connect it to its receiver with external conductors, agrounded shield wire may be used to avoid noise pick up on the conductors. Generally, one-point
grounding is recommended. When the thermocouple is not grounded, ground the instrument. Whenshielded conductors are supplied with our product, the sheath section will be grounded due to mounting
conditions. Therefore, the following two methods are available:( A similar method is recommended
when connecting the temperature sensor and the shielded external lead wires on site.)a) When a grounding conductor is not available at the end of the lead wire, make attachment between
the sheath and shield, and ground the sheath.
b) When a grounding conductor is available at the end of the lead wires the sheath and shield are
insulated to avoid 2-point grounding since grounding is normally done on the part of the instrument.
As shown in the figure of the grounding type of Fig. 8, a shield recommends you the method ofgrounding in the same part as grounding of a thermocouple.

16

OKAZAKI MANUFACTURING COMPANY

TD-1002b

INSTRUCTION MANUAL

Fig.8 Grounding of Shield(4) Caution after wiring
After the external conductors are connected, take care not to leave any dust or wire strips inside theterminal head. If wire strips are left, it will cause a short circuit or insulation deterioration. After
connecting, tightly close the cover to prevent any permeation of rain water, etc. If an adaptor or the likeis attached to the wiring port, confirm that the threads are screwed tight.

OKAZAKI MANUFACTURING COMPANY

17

TD-1002b

INSTRUCTION MANUAL

CHAPTER 6 SAFETY USE
6.1

Maintenance
Maintenance is important for safe and sure temperature measurement and control. Although
maintenance methods differ depending on the operation, we recommend the following:(1) Systematization of maintenance work
(2) Education and training to maintenance workers(3) Security of maintenance workers(4) Standardization of maintenance(5) Accuracy control of the inspection equipment (Recalibration)(6) Preparation and management of the maintenance data

6.2

Maintenance and Inspection
Since the maintenance and inspection of installed temperature sensors vary depending on the installation
place and purpose, they cannot be handled identically. General methods are listed below for yourreference.
(1) Daily maintenance and inspection
The temperature sensor cannot inform you of a temperature until it is connected to its receiver. An
abnormality, if any, can be detected in an early stage by confirming that the temperature indicated by thereceiver is within a normally expected temperature range. When there is another temperature sensor
near the measuring point, you can compare the reading between the two temperature sensors.
In case of the sensor with a terminal box, an O-ring may be deteriorated by the ambient environment(light, ozone, etc.). Recommend the operation check and part replacement at the time of regularinspection every year, although there may be no problem for more than a few years depending on theambient environment.
(2) Confirmation of the working conditions
The type and shape of the temperature sensor depends on its installation place and temperature.
Particularly, conditions such as atmosphere, temperature, pressure, flow speed, etc. have a great effecton determining what materials are used to build the temperature sensor as well as the size andconfiguration. Make sure that the working conditions have not changed. If they have changed, it isnecessary to confirm that the current temperature sensor will still be suitable. If it is not suitable, replace
the temperature sensor with one that will meet the working conditions.
(3) Confirmation of the insertion length
If the insertion length of the temperature sensor into the object being measured changes, heat conduction
from the outside also changes and an error may occur. In the case of thermocouple, an error may occur if
there is deterioration of the wires creating a non-uniformity. Confirm that the initial condition of thewires upon installation have remained unchanged.
(4) Confirmation of the measuring current value
The resistance thermometer sensor has a current flowing to the element for measurement of its
resistance value. This "measuring current" value should be maintained in order to provide a continuing
level of accuracy. If the normal current changes, there will be a change in self heating that can cause anerror in measurement. Make sure that the normal current is maintained.
(5) Cleaning and inspection of the protection tube
Soot, dust, sludge, etc., when accumulated onto the protection tube during use may worsen heat
conductivity to the temperature sensor inside and result in a measurement error. Clean them periodically.

18

OKAZAKI MANUFACTURING COMPANYINSTRUCTION MANUAL

TD-1002b

The protection tube is attached to protect the temperature sensor against the measurement atmosphere.
Make sure that it has not been corroded or oxidized and that it is free from mechanical damage. Whenremoving the temperature sensor for inspection, see that no foreign substance has entered the protection
tube. Clean the inside if necessary. Make sure that water does not get inside the protection tube as it cancause various problems.
(6) Inspection of the installation area and its operating conditions
The temperature sensors are sometimes installed with screws and flanges. Depending on the type of
installation, some sensors may be subjected to mechanical vibrations from pumps, power sources orforcible surges of the fluid. These external forces may loosen the clamped parts. When conditions aresevere, welded or brazed sections could be damaged, and allow air to enter or the fluid measured to leakout. Pay attention to the condition of temperature sensors, which can be checked visually.
(7) Inspection of insulation resistance
Check the measuring circuit for insulation resistance including the temperature sensor. A decrease of
insulation resistance can cause an indication error or induction problems. When the grounded typethermocouple is used, remove the thermocouple terminals and check the receivers circuit for insulation
resistance. (For checking insulation resistance of the temperature sensor, refer to Section 3.4. The
criterion for replacement is resistance value of 1MΩ minimum.
(8) Inspection of the connections
Check each connection in the measuring circuit for its condition and polarity. In the case of athermocouple, reversed polarity results in a large error.
(9) Inspection of the external conductors
The temperature sensor and receiver are wired to each other with external conductors. If the external
conductors are damaged or the wrong type of compensation lead wires are connected, a measurement
error can occur. Check for continuity, insulation resistance, reverse polarity, type and appearance of thecompensating lead wires.
(10) Periodic Inspection
Even if the temperature sensor is operating properly, it is recommended that the sensor be removed fromthe measurement point and calibrated in comparison with a standard thermometer once or twice a year.
However, as for Type K thermocouples used at 250℃ or higher, temperature reading may indicate ahigher value due to the effect of SRO if the immersion length at the time of periodic inspection is shorter
than the immersion length in use at site. Additionally, if Type K thermocouples are used in ahigh-temperature furnace with a deep immersion length, temperature reading may indicate beyond thelimit of error due to SRO at the time of periodic inspection with shorter immersion length. Thesephenomena are attributed to the heterogeneity of the thermocouple wires due to the influence of theambient temperature during use. When the temperature gradient is added to the inhomogeneous part, anerror in temperature reading will appear more notably. (Refer to Table 1 in Section 3.3.)
In addition, as specified in the next page, in the case of a temperature sensor mounted with a ferrule and aflange, etc. for food-grade sanitary standards, there is a very short insertion length of the product from thelimitations of the mounting portion. In particular, in the case of resistance thermometer sensor whichattaches the resistance element at the tip, there is a possibility that insufficient insertion error occurs at thetime of product installation when the insertion length is 60mm or less. And furthermore, in the case of
performing the re-inspection, it does not reach the actual temperature of the temperature bath unless it isimmersed in the test temperature bath until the ferrule and the flange portion, shows a large error.
Here is an example of the temperature sensor having extremely short insertion length with a ferrule. In
OKAZAKI MANUFACTURING COMPANY

19

TD-1002b

INSTRUCTION MANUAL

fact, based on the re-inspection performed by customer, the insertion length of
the sensor that error occurred was 30 mm or less.
In the case of performing the re-inspection of the sensor having the short
insertion length, the correct temperature may not be measured when only thesensor below the ferrule immersed into the test bath because the heat dissipation
by ferrule is large.

6.3

Periodic inspection of Temperature Sensor
Long term stability of temperature sensors depend on the type of installation, the measuring temperatureand its environment. The frequency of replacement will depend on the working conditions and can be
determined by temperature inspection at constant intervals along with daily maintenance and inspection.
Stable temperature control for most processes can be obtained by carrying out the above-mentioned
accuracy control. There are various inspection methods available, depending on the type of the temperature
sensor used and the inspection temperature available. The following describes a general inspection method
for your reference.
(1) Fixed point inspection
This method uses a standard fixed point as a temperature reference. It is effective for calibrating a specifictemperature with high accuracy and mainly used for the calibration of primary standards.
Table 9 ITS-90 Defined Fixed Points
Material and Its StateK°C

Triple point of equilibrium hydrogen
Triple point of neon
Triple point of oxygen
Triple point of argon
Triple point of mercury
Triple point of water
Melting point of gallium
Freezing point of indium
Freezing point of tin
Freezing point of zincFreezing point of aluminum
Freezing point of silver
Freezing point of cupper13.8033
24.556154.3584
83.8058
234.3156
273.16302.9146
429.7485505.078692.677
933.473
1234.931357.77-259.3467-248.5939-218.7916-189.3442-38.8344
0.01
29.7646156.5985
231.928
419.527660.323961.781084.62

Nonetheless, the defined fixed points are specified as Table 9, ITS-90 (International Temperature Scale
1990), the other test temperature is usually used for general temperature sensors. Please note that there is a
restriction on the length and the outer diameter of the temperature sensor in the case of using these
fixed-point devices.
In general, the test cannot perform with insufficient insertion length. Our temperature sensor calibration
section has performed the JCSS calibration and can perform the calibration in the part of the defined fixed
point. When testing a resistance thermometer or a thermocouple, the boiling point of nitrogen, oxygen or
water and the freezing point of water are used, and the Comparative inspection is used for these tests
instead of the above Fixed point inspection.
20

OKAZAKI MANUFACTURING COMPANY

TD-1002b

INSTRUCTION MANUAL(2) Comparative inspection
This is the method most frequently used. In general, this method uses a laboratory calibrated temperature
sensor as a standard. The inspection is performed by comparing the readings of the standard probe against
the readings of the test probe.
Unlike fixed calibration, this method enables the use of a wide range of inspection temperatures.
The typical test devices and testable temperature range are specified in Table 10.
Please note that the test devices are depending on the test temperature and there is a restriction on the lengthand the outer diameter of the temperature sensor.
The temperature sensor especially for food-grade sanitary standards, the insertion length is short due to therestriction of size at the installing part. In that case, our company can manufacture the sensor with longer
length, and then adjust it to the requested length before delivery. Accordingly, the error may become bigger
due to lack of insertion length at the time of re-inspection or in the installed state of the product.
In the case of a resistance thermometer sensor, care is required for the insertion length 60 mm or lessbecause the resistance element is attached to the tip.
Table10 Inspection Temperatures
Bath or furnace
Liquefied helium
Liquefied nitrogen
Liquefied oxygen
Low-temperature dry wellLow-temperature bath
Water bath
Oil bath
Niter bathElectric furnace

Inspection Temperature Range-269°C-196°C-183°C-100°C ~ -40°C-80°C ~ R.T.
R.T. ~ 80°C
80°C ~ 200°C
200°C ~ 500°C
400°C ~ 1050°C

Fig.9 Comparison method(3) Deviation method
This method is similar to comparative inspection and convenient for
inspection of a large amount of thermocouples. The inspection setup isalmost the same as mentioned in (2). This method is done by taking athermocouple identical to the test thermocouples and calibrating it at astandard temperature. It can then be insert into the calibration bath together
with the thermocouples to be tested and the difference between theirelectromotive forces can be measured. This method does not required areference junction. Our thermocouples are tested in this method.
(4) Field inspection
This method is used for calibration in the field where the temperature
sensors are actually used. As this is a simpler method, calibration accuracy
is inferior to the methods mentioned above. This method generally does
not require special equipment. Accumulation of calibration data
periodically is a practical method to judge whether the temperature
Fig. 10 Deviation method
sensor in use is still functioning or should be replaced.
a) Replacement method
OKAZAKI MANUFACTURING COMPANY

21

TD-1002b

INSTRUCTION MANUAL

Replace the temperature sensors are in use with a calibrated temperature sensor and compare theirindicated temperature values. When using this method, the temperature of the object measured
must be stable for a long period of time. When taking the measurement, it is necessary to allow
sufficient time for any delay in response when protection tube is installed. It may also be necessary toadjust the insertion length.
b) Parallel insertion method
Install a calibrated temperature as close as possible to the temperature sensor in use and compare theirindicated temperature values. This method requires an insertion hole or protection tube to be installedin advance that is parallel to the temperature sensor in use. Both sensors must be measured at the same
insertion depth. It is also necessary to have thermocouple junction area or RTS sensing area of the two in
direct contact.

22

OKAZAKI MANUFACTURING COMPANY

TD-1002b

INSTRUCTION MANUAL

CHAPTER 7 TROUBLESHOOTING
7.1

Identifying Problems
A problem with a temperature sensor is normally detected through an error in temperature indication.
Since all of temperature indication errors are not caused by the temperature sensor, it is necessary toaccurately grasp what is causing the problem. The most frequent problem causes would be breakage ordefects in the insulation of the thermocouple or resistance thermometer bulb.

7.2

Troubleshooting for Thermocouples
Table 11 Troubleshooting for Thermocouples

TroubleA temperature
indication scales
out to the minus
side

Occurrence Timing
Upon
DuringStart-up
Operation
OO

A temperature
indication scales
out to the plusside
The temperature
sensor indicatesclose to a room
temperature

O

O

O

O

O

O
O

A temperature
indication remains
unchanged if thetemperaturechanges.
Unstable
indication.

O

O

O

O

O
An indication value
is abnormal.
O

O

OKAZAKI MANUFACTURING COMPANY

Possible Cause

Remedy• The polarity of the sensor at either the receiveror thermocouple is reversed• Burn out setting of the receiveris at the lower limit and thethermocouple or compensation
lead wires are open circuited or the terminal
block has no power continuity.
•Trouble of the receiver.
• Burn out setting of the receiver is at the upper
limit, and the thermocouple or compensating
lead wires are snapped or the terminal block has
no power continuity.
•Trouble of the receiver.
•The input connection terminal orcompensating junction of thereceiver is short-circuited.
•Internal short-circuit of thecompensating lead wires.
•Trouble of the receiver.
• Open circuit in thermocouple.
• Open or short circuit of thecompensating lead wires.
• Trouble at the receiver. (No burnout circuit)• Check and connect correctly.

• Intermittent open circuit of thethermocouple or compensating
lead wires.
• Contact failure at the terminal block.
• Trouble at the receiver• Electric noise interference.
• Effect of fluctuation of the fluid
temperature to be measured.
• Mismatch of thermocouple orcompensating lead wires.
• Different polarity of thecompensating lead wires.
• Faulty installation of the thermocouple• Type of the receiver or range
setting is wrong.
• Deterioration of the thermocouple's
thermoelectromotive force• Deterioration of insulation of thethermocouple or compensating
lead wires.
• Change of thermocouple installation.
• Trouble in the receiver.

• Check for snapping andcontinuity with a tester, andreplace or reconnect theterminals.
• Check and repair or replace• Check for snapping andcontinuity with a tester, andreplace or reconnect theterminals.
• Check and repair or replace• Check the connection
terminals and remove the causeof short-circuit.
• Check for continuity with atester, and repair or replace.
• Check the circuit of thethermocouple & v
compensating
lead wires and instrument.
• Repair or replace.
• Check for continuity with anohmmeter and replace orreconnect the terminals.
• Check and repair or replace.
• After a check, change thegrounding method or shield.
• Change to the slower response
thermocouple.
• Check and set again or change
the connection• Check installation position,
insertion length, and installation
method, and reinstall.
• Check and set again.
• Replace• Replace• Check, and repair or replace.
• Check, and repair or replace.

23

TD-1002b

7.3

INSTRUCTION MANUAL

Troubleshooting for Resistance Thermometer Sensors
Table 11 Troubleshooting for Resistance Thermometer
TroubleNegativetemperature
indication

Occurrence Timing
Upon
DuringStart-up
Operation
O
O

O

O

Excessive positive
temperature
indicationO

Temperature
indication remains
unchanged if atemperaturechanges.
An indication value
is unstable.

O

O

O

O

O

O
An indication value
is abnormal.
O

O

An indication value
is several percent
higher.
An indication value
is several percent
lower.

24

O
O

Possible Cause

Remedy• Faulty 3 -wire type connection• Short -circuit at the resistanceelement block..
• Burnout setting of the receiveris at the lower limit, and theresistance element or extension
conductors are open or theterminal block has no continuity• The resistance element is
open circuit.
• Burnout setting of the receiveris at the lower limit, and theresistance element or extension
conductors are open or theterminal block has no continuity• Trouble in the receiver.

• Check and connect correctly.
• Check for short circuit with an ohmmeter orreconnect the terminals• The input connection terminal
or compensation junction of thereceiver is short-circuited• Internal short-circuit of thecompensation lead wires.
• Trouble in the receiver.
• Faulty resistance value of theresistance element.
• Faulty installation of theresistance thermometer sensors.
• Type of the receiver or settingof the range is wrong.
• Deterioration of insulation of
the resistance thermometer
sensor or
extension conductors.
• Change of installation of theresistance thermometer sensor.
• Trouble of the receiver.
• A "JPt" type resistancethermometer sensor is connected
to a "Pt" type instrument.
• A "Pt" type resistancethermometer sensor is connected
to a "JPt" type instrument• Check for open circuit with an ohmmeter,
and replace or reconnect the terminals.
• Check and repair or replace.
• After a check, change thegrounding method or shield.

• Check for open circuit with an ohmmeter,
and replace or reconnect
the terminals.

• Check, and repair or replace.

• Replace• Check for an installation
position, insertion length, and installation
method, and reinstall.
• Check the insulation resistance, and replace.
• Check the insulation, and repair or replace.
• Check the receiver , and repair or replace.

• Replace with an adequate one which meetsthe standard• Replace with an adequate one which meetsthe standard.

OKAZAKI MANUFACTURING COMPANYINSTRUCTION MANUAL

TD-1002b

CHAPTER 8 BASIC SPECIFICATIONS AND STRUCTURE OF TEMPERATURE SENSORS
8.1

Protection Tube Type Temperature Sensors
This is a type of temperature sensor that has been used for many years. It is constructed with a solid
insulator type thermocouple or mica insulated/fin type resistance thermometer sensor inserted into theprotection tube. The protection tube is used to protect the thermocouple or resistance thermometer sensor
against ambient environments. Stainless steel is the most often used material. A flange or screw is weldedto the protection tube for installation. It is an inexpensive sensor due to its simple structure and widely
used.
(1) Insulator type thermocouple
The insulator type thermocouple consists of thermocouple wires, insulators, terminal box, and protection
tube. The tip of the thermocouple is welded to create a measuring junction. For high-temperature
measurement, platinum thermocouple wires (B, R, S) are used with a ceramic protection tube.
(2) Fin type resistance thermometer sensor
The fin type resistance thermometer sensor is also called a general resistance thermometer sensor. Its
basic structure is exactly the same as that of the insulator type thermocouple, except a temperature sensing
element is used. Originally supplied with a mica type resistance element, it currently uses a CERACOIL
element (refer to Remarks below) to enhance strength and insulation of the element block.

(Remarks)
CERACOIL : Okazaki product name for the ceramic insulated
very fine platinum wire coil. It is used as the element of thesheathed resistance thermometer sensor.
Fig. 11 Structure of Protection Tube Type
Temperature Sensor

OKAZAKI MANUFACTURING COMPANY

25

TD-1002b
8.2

INSTRUCTION MANUAL

Sheathed Temperature Sensor
The most popular type of temperature sensors are made with metal sheath mineral insulated cable. Knownas Ml cable, it is supplied with thermocouple wire or resistance thermometer conductors. The insulation in
the tube is highly compacted magnesium oxide (MgO) powder. Various outer diameters can be
manufactured, ranging from 0.08 mm to 12.7 mm O.D. Very long
sheaths can be also manufactured. The sheathed temperature sensor uses
the tip of the cable as a temperature sensing area. By carefully selecting aproper sheath material, these temperature sensors can be used under
extreme environments without using the protection tubes. Fig.12 shows
sectional views of the sheath, and Fig.13 a structural view of the mostpopular types of sheathed temperature sensors.
Normally, the sheathed thermocouple has a measuring junction inside thesheath to create the temperature sensing area. The sheathed resistancethermometer sensor has a resistance element (CERACOIL) embedded at
the tip of the sheath as the temperature sensing area.
Note that the front end of about 70 mm can not be bent because it
Fig. 12 Section of Sheathcontains the sensing element.

Fig. 13 Structure of Sheathed Temperature Sensor

The sheathed thermocouple is referred to as AEROPAK, and the sheathed resistance thermometer sensor is
RESIOPAK. A typical sheath outer diameter is 3.2 mm to 8.0 mm O.D. The sheathed temperature sensors
26

OKAZAKI MANUFACTURING COMPANY

TD-1002b

INSTRUCTION MANUAL

with a thin outer diameter of 4.8 mm O.D. or less are installed in various places because they can be easily
bent by hand. The recommended minimum bending radius is twice the sheath outside diameter. Bendingor straightening a temperature sensor with a smaller diameter will break the conductors. However, incase of bending at local by customer, we recommend that the bending radius is 5 times or over of thesheath outside diameter.
The connection head type of temperature sensor shown in Fig.13 is often combined with the protection
tube and is used for process control in various types of plants. The measuring junction, which is thetemperature sensing area of the thermocouple, has several types of configurations as shown in Fig.14.
Proper selection depends on the applications. Extra care should be taken when using the pressure-tight
explosion proof temperature sensor. In this case, the measuring junction is limited to the un-grounded typeonly in Japan

Fig. 14 Measuring junction types

8.3

Explosion-proof Temperature sensor
In oil refining plants, gas manufacturing plants,

and chemical plants, many areas aredesignated as hazardous. These areas where a
combustible gas or inflammable steam ismixed with the air and can generate an
atmosphere, which is likely to explode if there
are any sparks. When using electric appliancesin the hazardous areas, there are various
restrictions set up for their enclosures to insurethat explosions will not occur due to the sparks
produced by the electric appliances. Those
restrictions are the “Explosion-proof
Structural Standards for Electric Machines andAppliances (Notification N0.16 of Ministry ofLabor, 1969)". These standards apply totemperature sensors (thermocouples andresistance thermometer sensors) because they are also classified therein as measuring instruments.
Since our explosion-proof temperature sensors have been designed following those standards and passed
the verification by an official authorization organization, they can be safely used in the hazardous area.
There are five types of explosion-proof structures. Of them, only the following two types are applied totemperature sensors.
(1) Flame-proof structureThis is a fully enclosed structure. It can be defined that when gas or steam finds its way into a container andcauses an explosion, the said structure contains the explosion pressure, and a flame caused by the explosion
27

OKAZAKI MANUFACTURING COMPANY

TD-1002b

INSTRUCTION MANUAL

does not ignite the gas or steam outside the said container.
Currently, our products have passed the verification of the Flame-proof grade d2G4 or Exd II BT4. When
wiring the external conductors through the wiring port, it is necessary to employ either pressure-tightpacking type adapter or conduit tube screw coupling system at the wiring port (conduit). External wiring of
the sensor is the user's responsibility and should be installed based on applicable explosion proof guidelines.
Note that, especially, Exd type Flame-proof product require the use of pressure-proof packing typeadaptors.
Based on the recent increase demand for products complying with explosion-proof standards for eachcountry, we have started manufacturing products in compliance with respective standards in EU countries,
the United States, China and South Korea. These products are adapted to the standards of each country, but
are not for use in Japan.
(2) Intrinsic safety explosion-proof structure
In this structure, the sparks and heat produced in the electric circuits of the electric machines and appliances
cannot become an ignition source for the explosive atmosphere.
For the temperature sensor, a safety isolator (Zener barrier) is installed in a safe place to prevent electricenergy from flowing into the hazardous area and becoming an ignition source when there is a problem with
the instrument. When combining the temperature sensor with the safety isolator, it is necessary to select thesafety isolator which is suitable for the electrical characteristics (inductance and capacitance) of thetemperature sensor. Currently, a combination of our temperature sensors with Yokogawa Electric-madesafety barriers (BARD series), Nakamura Electric Manufacturing Company’s (NZB series) and MTL
Instruments’ (MTL series) are authorized by a government department. There are few restrictions forthermometer sensor combinations. Please refer to the Table 13.
However, in European countries and USA, temperature sensors (thermocouple and resistancethermometer) do not need to be certified because of small amount of energy reservation. Therefore, thesesensors can be used without being certified under permissible range ofsafety barriers.
Table 13 Possible combination of Thermometers and Safety Barriers*Type

Element

Model

Thermocouple:
Resistance
Thermocouple

SingleDoubleSingleSingle*1
BARD600x2
BARD700
NZB2-1R52

ResistanceB

SingleNZB3-1R75e*2
Resistancec

Double

MTL5082

1

Class
i3aＧ5
Exia
ⅡCT5
Exia
ⅡCT3

Certificate

Internal
Resistance

Allowable
Ｌ

Allowable
Ｃ

Manufacturer

T34599
T34600
T34601
TC14292235±15Ω
130±15Ω
52Ω

(1.6Mh+LW)
0.8mH
0.45mH
0.51mH(0.5μF+CW)
0.1μF
0.1μF
1.7μF

TC1429375Ω

0.51mH

1.7μF

TC17865

Insulated

48.5mH

21μF

Yokogawa
Electric
Corporation
Nakamura
Electric Mfg.
Co., Ltd.
CooperIndustries
Japan K.K.

Cause of separately certification, it can be used with safety barriers which have allowed value ( ). BARD 600 is acceptable.
*2 : Resistance thermometer has double elements with single safety barrier,therefore, one circuit of resistance thermometer is used as
an extra. (sensor limited type)
LW : Inductance of outside lead wire
CW : Capacitance of outside lead wire
Note 1 : For NZB series made by Nakamura Electric Mfg. Co., Ltd., label of certification shall be supplied
Note 2: There is an option other than above of insulating barriers made by Cooper Industries Japan K.K. and P+F can use for athermocouple (single). Please contact us if you need further information.

28

OKAZAKI MANUFACTURING COMPANYINSTRUCTION MANUAL

8.4

TD-1002b

Lead Wire Type Temperature sensor (Thermocouple type, Resistance thermometer sensor type)The lead wire type temperature sensor that enables the temperature measurement where are difficult tomount the sheath type temperature sensor, and it is generally consisted by insulated with glass fiber orresin-coated insulated wire. The resistance element shall be incorporated in the temperature sensing partfor a resistance thermometer sensor.
For example, in case of installing a temperature sensor into a bearing, the sheath type temperature sensor
may be difficult to install. Since the temperature-sensitive element (or temperature measuring junction) is
incorporated in the inside of a metal tip that applied to the tip of the lead wire type temperature sensor, andit can be bent at the close part of the temperature sensing part, the lead wire type temperature sensor isenabled to install in a narrow place. However, extreme bending is strictly prohibited.

OKAZAKI MANUFACTURING COMPANY

29

TD-1002b

INSTRUCTION MANUAL

CHAPTER 9 REFERENCE MATERIAL
9.1

Thermocouple Reference Thermo-electromotive Force Table
Table 14

Reference Thermo-electromotive Force Table
V

B Thermocouple
0

10

20

30

40

50

60

70

80

90

100

0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800

0
33
178
431
787
1 242
1 792
2 431
3 154
3 957
4 834
5 780
6 786
7 848
8 956
10 09911 26312 433
13 591

-2
43
199
462
828
1 293
1 852
2 499
3 230
4 041
4 926
5 878
6 890
7 957
9 069
10 215
11 38012 54913 706

-3
53
220
494
870
1 344
1 913
2 569
3 308
4 127
5 018
5 976
6 995
8 066
9 182
10 331
11 497
12 66613 820

-2
65
243
527
913
1 397
1 975
2 639
3 386
4 213
5 111
6 075
7 100
8 176
9 296
10 447
11 61412 782

0
78
267
561
957
1 451
2 037
2 710
3 466
4 299
5 205
6 175
7 205
8 286
9 410
10 563
11 731
12 898

2
92
291
596
1 002
1 505
2 101
2 782
3 546
4 387
5 299
6 276
7 311
8 397
9 524
10 67911 84813 014

6
107
317
632
1 048
1 561
2 165
2 854
3 626
4 475
5 394
6 377
7 417
8 508
9 639
10 796
11 96513 130

11
123
344
669
1 095
1 617
2 230
2 928
3 708
4 564
5 489
6 478
7 524
8 620
9 753
10 91312 08213 246

17
141
372
707
1 143
1 675
2 296
3 002
3 790
4 653
5 585
6 580
7 632
8 731
9 868
11 02912 19913 361

25
159
401
746
1 192
1 733
2 363
3 078
3 873
4 743
5 682
6 683
7 740
8 844
9 984
11 146
12 31613 476

33
178
431
787
1 242
1 792
2 431
3 154
3 957
4 834
5 780
6 786
7 848
8 956
10 09911 26312 433
13 591

°C

0

-10
- 51
10
54
723
1 558
2 498
3 512
4 580
5 697
6 861
8 073
9 333
10 638
11 986
13 367
14 77016 181
17 59118 98820 356

-30
- 145
30
171
879
1 739
2 696
3 721
4 800
5 926
7 100
8 321
9 590
10 905
12 26013 64615 05216 46417 87219 26420 620

-40
- 188
40
232
959
1 831
2 796
3 827
4 910
6 041
7 220
8 446
9 720
11 03912 397
13 78615 19316 60518 01219 40220 749

-50
- 226
50
296
1 041
1 923
2 896
3 933
5 021
6 157
7 340
8 571
9 850
11 17312 535
13 92615 33416 74618 15219 54020 877

-60

-70

-80

-90

-100

60

70

80

90

363
1 124
2 017
2 997
4 040
5 133
6 273
7 461
8 697
9 980
11 307
12 67314 06615 47516 88718 29219 67721 003

431
1 208
2 112
3 099
4 147
5 245
6 390
7 583
8 823
10 111
11 44212 81214 20715 616
17 02818 431
19 814

501
1 294
2 207
3 201
4 255
5 357
6 507
7 705
8 950
10 242
11 57812 95014 34715 75817 16918 57119 951

573
1 381
2 304
3 304
4 363
5 470
6 625
7 827
9 077
10 37411 71413 08914 48815 89917 31018 71020 087

100
647
1 469
2 401
3 408
4 471
5 583
6 743
7 950
9 205
10 506
11 85013 22814 62916 04017 45118 84920 222

-30
- 150
30
173
872
1 698
2 599
3 548
4 532
5 546
6 593
7 673
8 787
9 935
11 11312 31213 52314 73615 94217 13118 285

-40
- 194
40
235
950
1 786
2 692
3 645
4 632
5 649
6 699
7 783
8 900
10 051
11 23212 43313 64414 85716 06217 24918 395

-50
- 236
50
299
1 029
1 874
2 786
3 742
4 732
5 753
6 806
7 893
9 014
10 16811 351
12 55413 766
14 97816 18217 36618 503

-60

-70

-80

-90

-100

60

70

80

90

365
1 110
1 962
2 880
3 840
4 833
5 857
6 913
8 003
9 128
10 285
11 471
12 67513 88715 09916 301
17 48318 609

433
1 191
2 052
2 974
3 938
4 934
5 961
7 020
8 114
9 242
10 403
11 59012 79614 00915 22016 42017 600

502
1 273
2 141
3 069
4 036
5 035
6 065
7 128
8 226
9 357
10 52011 710
12 91714 13015 341
16 53917 717

573
1 357
2 232
3 164
4 134
5 137
6 170
7 236
8 337
9 472
10 638
11 83013 03814 25115 461
16 65817 832

100
646
1 441
2 323
3 259
4 233
5 239
6 275
7 345
8 449
9 587
10 757
11 95113 15914 37315 58216 777
17 947V

R Thermocouple
0

0

°C

0

0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
1600
1700

0
647
1 469
2 401
3 408
4 471
5 583
6 743
7 950
9 205
10 506
11 85013 22814 62916 04017 45118 84920 222

°C

0

-20
- 100
20
111
800
1 648
2 597
3 616
4 690
5 812
6 980
8 197
9 461
10 77112 12313 507
14 911
16 32317 73219 12620 488

0

0

°C

0

0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
1600
1700

0
646
1 441
2 323
3 259
4 233
5 239
6 275
7 345
8 449
9 587
10 757
11 95113 15914 37315 58216 777
17 947

-10
- 53
10
55
720
1 526
2 415
3 355
4 332
5 341
6 381
7 454
8 562
9 703
10 87512 07113 28014 49415 70216 89518 061

-20
- 103
20
113
795
1 612
2 507
3 451
4 432
5 443
6 486
7 563
8 674
9 819
10 99412 191
13 40214 61515 82217 01318 174

ITS-90V

S Thermocouple30

ITS-90°C

ITS-90OKAZAKI MANUFACTURING COMPANY

TD-1002b

INSTRUCTION MANUAL

°C
-200
-100
0
°C
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300

°C
-200
-100
0
°C
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300

°C
-200
-100
0
°C
0
100
200
300
400
500
600
700
800
900
1000

0
-5 891-3 554
0
0
0
4 096
8 138
12 20916 39720 64424 90529 12933 27537 32641 27645 11948 83852 4100-3 990-2 407
0
0
0
2 774
5 913
9 341
12 97416 74820 61324 52728 45532 37136 25640 08743 84647 5130-8 825-5 237000
6 319
13 421
21 03628 94637 00545 09353 11261 01768 78776 373

K Thermocouple-20-30-6 158-6 262-4 138-4 411- 778-1 156
20
30
798
1 203
4 920
5 328
8 940
9 343
13 04013 45717 24317 66721 49721 92425 75526 17929 96530 38234 09334 50138 12438 52242 05342 44045 87346 24949 56549 92653 10653 451-10-6 035-3 852
- 392
10
397
4 509
8 539
12 62416 82021 07125 33029 54833 68537 72541 66545 49749 20252 759-10-4 083-2 612
- 260
10
261
3 072
6 245
9 696
13 34617 131
21 00324 91928 84732 76136 64140 46644 218-10-9 063-5 681
- 582
10
591
6 998
14 16421 81729 74737 81545 90053 90861 80169 554

N Thermocouple-20-30-4 162-4 226-2 808-2 994
- 518
- 772
20
30
525
793
3 374
3 680
6 579
6 916
10 054
10 41313 71914 09417 51517 90021 39321 78425 31225 70529 23929 63233 15133 54137 02737 41140 84541 22344 58844 958E Thermocouple-20-30-9 274-9 455-6 107-6 516-1 152-1 709
20
30
1 192
1 801
7 685
8 379
14 91215 66422 60023 38630 55031 35438 62439 43446 70547 50954 70355 49762 58363 36470 31971 082

OKAZAKI MANUFACTURING COMPANY-40-6 344-4 669-1 527
40
1 612
5 735
9 747
13 87418 09122 35026 60230 79834 90838 91842 82646 62350 28653 795-40-4 277-3 171-1 023
40
1 065
3 989
7 255
10 77414 46918 28622 17526 09830 02433 93037 79541 60045 326-40-9 604-6 907-2 255
40
2 420
9 081
16 42024 17432 15940 24348 31356 28964 14471 844-50-6 404-4 913-1 889
50
2 023
6 138
10 15314 29318 516
22 77627 02531 21335 31339 31443 21146 99550 64454 138-50-4 313-3 336-1 269
50
1 340
4 302
7 597
11 13614 846
18 67222 56626 49130 41634 31938 17941 97645 694-50-9 718-7 279-2 787
50
3 048
9 789
17 18124 96432 96541 05349 11657 08064 92272 603-60-6 441-5 141-2 243
60
2 436
6 540
10 56114 71318 941
23 20327 44731 62835 71839 70843 59547 36751 00054 479-60-4 336-3 491-1 509
60
1 619
4 618
7 941
11 50115 22519 05922 95826 88330 80734 70738 56242 35246 060-60-9 797-7 632-3 30660
3 685
10 50317 94525 75733 77241 86249 91757 87065 69873 360-70-6 458-5 354-2 587
70
2 851
6 941
10 97115 13319 36623 62927 86932 04136 12140 10143 97847 73751 35554 819-70-4 345-3 634-1 744
70
1 902
4 937
8 288
11 86715 60419 44723 35027 27631 19935 09538 94442 72746 425-70-9 835-7 963-3 81170
4 330
11 22418 71326 55234 57942 67150 71858 65966 47374 115

-80

V
-90

ITS-90-100-5 550-2 920
80
3 267
7 340
11 38215 55419 79224 05528 28932 45336 52440 49444 35948 10551 708-5 730-3 243
90
3 682
7 739
11 79515 97520 21824 48028 71032 86536 92540 88544 74048 47352 060-5 891-3 554
100
4 096
8 138
12 20916 39720 64424 90529 12933 27537 32641 27645 11948 83852 410

-80

V
-90

ITS-90-100-3 766-1 972
80
2 189
5 259
8 637
12 23415 98419 83523 74227 66931 59035 48239 32643 10146 789-3 884-2 193
90
2 480
5 585
8 988
12 60316 36620 22424 13428 06231 98135 86939 70643 47447 152-3 990-2 407
100
2 774
5 913
9 341
12 97416 74820 61324 52728 45532 37136 25640 08743 84647 513-80-8 273-4 30280
4 985
11 951
19 48427 34835 38743 47951 51759 44667 24674 869V-90-8 561-4 77790
5 648
12 68420 25928 14636 19644 28652 31560 23268 01775 621ITS-90-100-8 825-5 237100
6 319
13 421
21 03628 94637 00545 09353 11261 01768 78776 37331

TD-1002b

°C
-200
-100
0
°C
0
100
200
300
400
500
600
700
800
900
1000
1100
1200

0
-7 890-4 6330
0
0
5 269
10 77916 32721 84827 39333 10239 13245 49451 87757 95363 79269 553

INSTRUCTION MANUAL-10-8 095-5 037
- 501
10
507
5 814
11 33416 88122 40027 95333 68939 75546 14152 50058 54564 370

°C
-200
-100
0
°C
0
100
200
300
400

0
-5 603-3 379
0
0
0
4 279
9 288
14 86220 872-10-5 753-3 657
- 383
10
391
4 750
9 822
15 445

°C

0

0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
2100
2200
2300

0
1 451
3 090
4 865
6 732
8 657
10 60912 55914 49416 39818 26020 071
21 82523 52025 15526 72928 24329 69631 08732 41333 66934 84935 94036 931

10
135
1 608
3 262
5 048
6 922
8 851
10 80412 75314 686
16 58718 44420 24921 99723 68625 31526 88328 39129 83831 22232 54233 79134 96236 04437 024-20

J Thermocouple-30-5 426
- 995
20
1 019
6 360
11 88917 43422 95228 51634 27940 38246 78653 11959 13464 948-5 801-1 482
30
1 537
6 909
12 44517 98623 50429 08034 87341 01247 43153 73559 72165 525

V
-40

-50

-60

-70

-80

-90

ITS-90-100-6 159-1 961
40
2 059
7 459
13 00018 53824 05729 64735 47041 64548 07454 34760 30766 102-6 500-2 431
50
2 585
8 010
13 55519 09024 61030 21636 07142 28148 71554 95660 89066 679-6 821-2 893
60
3 116
8 562
14 11019 64225 16430 78836 67542 91949 35355 56161 47367 255-7 123-3 344
70
3 650
9 115
14 66520 19425 72031 36237 28443 55949 98956 16462 05467 831-7 403-3 786
80
4 187
9 669
15 21920 74526 27631 93937 89644 20350 62256 76362 63468 406-7 659-4 21590
4 726
10 22415 77321 29726 83432 51938 51244 84851 25157 36063 21468 980-7 890-4 633100
5 269
10 77916 32721 84827 39333 10239 13245 49451 87757 95363 79269 553T Thermocouple-20-30-5 888-6 007-3 923-4 177- 757-1 121
20
30
790
1 196
5 228
5 714
10 36210 90716 03216 624-40-6 105-4 419-1 475
40
1 612
6 206
11 45817 219-50-6 180-4 648-1 819
50
2 036
6 704
12 01317 819-60-6 232-4 865-2 153
60
2 468
7 209
12 57418 422-70-6 258-5 070-2 476
70
2 909
7 720
13 13919 030-5 261-2 788
80
3 358
8 237
13 70919 641C Thermocouple
20
30
273
413
1 766
1 926
3 436
3 610
5 232
5 417
7 113
7 305
9 046
9 241
10 99911 19512 94713 14114 87815 06916 77516 96218 62718 80920 42620 60322 16922 34023 85224 01725 47525 63327 03727 19028 53828 68529 97930 12031 35731 49132 67032 79733 91134 03135 07435 18636 14736 249

40
555
2 087
3 786
5 603
7 497
9 436
11 39013 33515 26017 14918 99120 77922 51024 18125 79227 34228 83130 26031 62532 92434 15135 29636 350

50
699
2 251
3 963
5 789
7 689
9 631
11 585
13 52915 45117 33519 17220 95522 68024 34525 94927 49328 97730 39931 75833 05034 26935 40636 449

60
846
2 415
4 141
5 976
7 882
9 827
11 78013 72315 641
17 52119 353
21 13022 84924 50826 10727 64529 12230 53831 89033 17534 38735 51536 548

70
994
2 582
4 321
6 164
8 075
10 022
11 97413 91615 83117 70719 53321 30523 01824 67126 26327 79529 26630 67632 02233 30034 50335 62336 645

80
1 145
2 750
4 501
6 353
8 269
10 21812 16914 10916 021
17 89219 71321 47923 18624 83326 41927 94529 41030 81332 15333 42434 61935 73036 742-80

V-90-5 439-3 089
90
3 814
8 759
14 28320 255

μV
90
1 297
2 919
4 682
6 542
8 463
10 41312 36414 301
16 21018 07619 89221 65223 35324 99426 57428 09429 55330 95032 28333 54734 73435 83636 837

ITS-90-100-5 603-3 379
100
4 279
9 288
14 86220 872

ITS-90
100
1 451
3 090
4 865
6 732
8 657
10 60912 55914 49416 39818 26020 071
21 82523 52025 15526 72928 24329 69631 08732 41333 66934 84935 94036 931

Remarks : The EMF tables given above completely conform to t he following standards
JIS C 1602 (Japan) IEC 584-1 (International) ASTM E 230 (U.S.A.)(C Thermocouple is specified in JIS C1602, IEC and ASTM standards issued in 2015.)

32

OKAZAKI MANUFACTURING COMPANY

TD-1002b

INSTRUCTION MANUAL

9.2

Color Codes for Compensating Cables
Table 15

Combined
Thermocouple
Symbol
B

+
Cu

−
Cu

R

Cu

Cu-Ni

Material
Code

Color Codes for Compensating Cables

JIS C 1610:2012
IEC 60584-3:2007
Insulator+−
Grey

SheathCode

Grey

Purple

BC
RCA
/RCB
SCA
/SCB
NX
KX
KCA
KCB
KCC
EX

JIS C 1610:1995
Division 2
Insulator
Sheath+−Grey

ASTM E230-2012
Insulator
+
−
Grey

S

Cu

Cu-Ni

N

E

Ni-Cr
Ni-Cr
Ni-Cr
Fe
Cu
Ni-Cr

Ni-Si
Ni-Al
Ni-Al
Cu-Ni
Cu-Ni
Cu-Ni

BC
RCA
/RCB
SCA
/SCB
NX
KX
KCA
KCB
EX

J

Fe

Cu-Ni

JX

Black

Black

JX

Yellow

W

T

Cu

Cu-Ni

TX

Brown

Brown

TX

Brown

Blue

K

OrangeOrange
Pink
Green
-

OrangeW-

Green
PurpleOKAZAKI MANUFACTURING COMPANY

Orange
Pink
Green
Green

W

Red

-

W

-

Black

Black

Black

Black

-

OrangeYellow
Purple

Blue
Red

W

PurpleSheath
Grey
Green

Red

Red

Green
OrangeYellow
Purple
Black
Blue

33

TD-1002b
9.3

INSTRUCTION MANUAL

Tolerance of Thermocouples
Table 16 Thermocouple Tolerances
Type
Ｂ

R&S

C

N&K

E

J

T

JIS C 1602:2015 / IEC 60584-2:2013
Temp. RangeClass
Tolerance
600°C〜1700°C
2±0.0025| t |°C
600°C 〜800°C±4°C
3
800°C 〜1700°C±0.005t °C±1°C or
0°C〜1600°C
1±[1+0.003 (t-1100 )]°C
0°C〜600°C±1.5°C
2
600°C〜1600°C±0.0025 | t |°C
426°C〜2315°C-40°C〜375°C
375°C〜1000°C-40°C〜333°C
333°C〜1200°C-167°C〜40°C-200°C〜-167°C-40°C〜375°C
375°C〜800°C-40°C〜333°C
333°C〜900°C-167°C〜40°C-200°C〜-167°C-40°C〜375°C
375°C〜750°C-40°C〜333°C
333°C〜750°C-40°C〜125°C
125°C〜350°C-40°C〜133°C
133°C〜350°C-67°C〜40°C-200°C〜-67°C

2
1
2
3
1
2
3
1
2
1
2
3

±0.01 | t |°C±1.5°C±0.004 | t |°C±2.5°C±0.0075 | t |°C±2.5°C±0.015 | t |°C±1.5°C±0.004 | t |°C±2.5°C±0.0075 | t |°C±2.5°C±0.015 | t |°C±1.5°C±0.004 | t |°C±2.5°C±0.0075 | t |°C±0.5°C±0.004 | t |°C±1.0°C±0.0075 | t |°C±1.0°C±0.015 | t |°C

ASTM E 230-2012
Temp. Range
Class
870°C 〜1700°C

STD.
SP.

0°C 〜1480°C
STD.
0℃ 〜2315°C

STD
SP.

0°C 〜1260°C-200°C 〜0°C

±0.6°C or±0.1%±1.5°C or±0.25%±4.4°C or±1％±1.1°C or±0.4%±2.2°C or±0.75%

STD.

±2.2°C or±2%

SP.

±1.0°C or
±0.4%

STD.

±1.7°C or
±0.5%

STD.

±1.7°C or±1%SP.

±1.1°C or
±0.4%

STD.

±2.2°C or±0.75%

SP.

±0.5°C or
±0.4%

STD.

±1.0°C or±0.75%

STD.

±1.0°C or±1.5%

0°C 〜760°C

0°C 〜370°C-200°C 〜0°C

±0.5%

STD.

0°C 〜870°C-200°C 〜0°C

Tolerance

1) Tolerance is referred to as the maximum allowable deviation between hot junction temperature and thetemperature derived from the EMF table.
2) ASTM temperature is C or % value for the measured temperature, which is greater.
3) | t | is the measuring temperature indicated by the temperature irrelevant to the symbol + or -.
4) Class 1, 2, or 3 conforms to the old JIS Class 0.4, 0.75 or 1.5, respectively.
5) JIS Standard is identical with IEC, BS or DIN Standard except for a part.
6) The tolerance of JISC1605 and JISC1602 is completely the same.
7) ASTM Standard is same as the old ANSI Standard.
8) Tolerances given in this table apply only to new wire as delivered to the user and do not allow for changes incharacteristics with use. (ASTM E230)
9) The standard tolerances shown do not apply to Type E mineral-insulated, metal-sheathed (MIMS)
thermocouples and thermocouple cables as described in Specifications E608/E608M and E585/E585M. The
standard tolerances for MIMS Type E constructions are the greater of 2.2°C or 0.75 % from 0 to 870°C andthe greater of 2.2°C or 2 % from -200 to 0°C.

34

OKAZAKI MANUFACTURING COMPANY

TD-1002b

INSTRUCTION MANUAL

9.4

Resistance Thermometer Sensor Reference Resistance Value Table
Table 17 JIS C 1604-1997/ IEC 60751-2008 Reference Resistance Value
Pt100 at 0°C

°C
-200
-100
0
°C
0
100
200
300
400
500
600
700
800

0
18.52
60.26
100.000100.00138.51
175.86212.05247.09280.98313.71345.28375.70R100/10=1.3851

Unit Ω

ITS-90

-10

-20

-30

-40

-50

-60

-70

-80

-90

-100

56.19
96.09
10
103.90142.29179.53215.61250.53284.30316.92348.38378.68

52.11
92.16
20
107.79146.07183.19219.15253.96287.62320.12351.46381.65

48.00
88.22
30
111.67149.83186.84222.68257.38290.92323.30354.53384.60

43.88
84.27
40
115.54153.58190.47226.21260.78294.21
326.48357.59387.55

39.72
80.31
50
119.40157.33194.10229.72
264.18297.49329.64360.64390.48

35.54
76.33
60
123.24161.05
197.71233.21
267.56300.75332.79363.67

31.34
72.33
70
127.08164.77201.31236.70270.93304.01335.93366.70

27.10
68.33
80
130.90168.48204.90240.18274.29307.25339.06369.71

22.83
64.30
90
134.71
172.17208.48243.64277.64
310.49342.18372.71

18.52
60.26
100
138.51
175.86212.05247.09280.98313.71345.28375.70

Table 18 JIS C 1604-1989 Reference Resistance Value
JPt100 at 0°C
°C

0

-200

17.14

-100

R100/10=1.3916

Unit Ω

IPTS-68

-10

-20

-30

-40

-50

-60

-70

-80

-90

-100

59.57

55.44

51.29

47.11

42.91

36.68

34.42

30.12

25.80

21.46

17.14

0

100.00

96.02

92.02

88.01

83.99

79.96

75.91

71.85

67.77

63.68

59.57

°C

0

10

20

30

40

50

60

70

80

90

100

0

100.00103.97107.93111.88115.81119.73123.64127.54131.42135.30139.16100

139.16143.01146.85150.67154.49158.29162.08165.86

169.63173.38177.13200

177.13180.86184.58188.29191.99195.67199.35203.01206.66210.30213.93300

213.93217.54221.15224.74228.32231.89235.45238.99242.53246.05249.56400

249.56253.06256.55260.02263.49266.94270.38273.80277.22280.63284.02500

284.02287.40

9.5

Resistance Thermometer Sensor Tolerances
Table 19 Resistance Thermometer Sensor Tolerances(Temperature range of wire-wound resistance element shall be in accordance with company standards)

Nominal resistancePt 100Ω at 0°C(R100/R0=1.3851)

Class

Tolerance (°C)

JIS C 1604:1997
IEC 751-1983

AA± 0.1+0.0017 | t |± 0.15+0.002 | t |± 0.13+0.0017 | t |± 0.3+0.005 | t |± 0.25+0.0042 | t |± 0.6+0.01 | t |-200~500-200~500-

ABC

IEC 60751:2008
Wire woundThin film
resistor
resistor
Temperature range (°C)
-196~450
0~150-196~450-30~300-196~600-50~500-196~600-50~600

ASTM E 1137

-200~650-200~650-

Remarks(1) Only the tolerances for resistance elements shall be specified in IEC 60751:2008/JIS C1604:2013(2) Since the criteria considering the uncertainty is incorporated in IEC 60751:2008/JIS C 1604:2013, the value from the specified tolerance
minus our uncertainty shall be the our tolerances at the time of delivery. In the company, as of April 2015, the uncertainty at 0 ℃ shall be 0.03 ℃
in all factories. If the length of sheath part is 700 mm or less, the uncertainty shall be 0.03 ℃ even if the B and b terminal is replaced.

OKAZAKI MANUFACTURING COMPANY

35

TD-1002b
9.6

INSTRUCTION MANUAL

Major Standards List
Table 20 Major standards list

Type

Country
Japan

I.N.

USA

Thermocouple

G.B.

Germany

Compensation
cable

Year

Name of standard

JIS

C 1602

1995

Thermocouples

JIS

C 1605

1995

Mineral insulated thermocouples

IEC60584-1

1995

Thermocouples Part 1:Reference Tables (Ed.2.0b:1995)

IEC60584-2

1982

Thermocouples Part 2: Tolerances (Amd.1 Ed.1.0b:1989)

IEC

61515

1995

Mineral insulated thermocouple cables and thermocouples (Ed.1.0b: 1995)

ANSI /ISA

MC96.1

1982

ASTM

E230

2012

ASTM

E608

2006

BS

4937

DeletedTEMPERATURE MEASUREMENT THERMOCOUPLES (Latest
year : 1982→ Move to ASTM E230)
Temperature-Electromotive Force (EMF) Tables for Standardized
thermocouples
Standard Specification for Metal-Sheathed Base-Metal Thermocouples(Reaproved-2004)
Part1〜 Part8: Reference Tables (Move to BS EN 60584-1)

BS EN

60584-1

1996

Thermocouples Part 1:Reference Tables

BS EN

60584-2

1993

Thermocouples Part 2:Tolerances

BS EN

61515

1996

DIN

43710

Deleted

DIN

43721

1980

Mineral insulated thermocouple cables and thermocouples
Measurement and control; electrical temperature sensors; Reference
Tables (Latest year :1985）
Measurement and control; electrical temperature sensors; mineralinsulated thermo cables and mineral insulated thermocouples

60584-1

1996

Thermocouples Part 1:Reference Tables

60584-2

1994

Thermocouples Part 2: Tolerances

61515

1996

Mineral insulated thermocouple cables and thermocouples
Extension and compensating cables for thermocouples
Thermocouples Part 3:Extension and compensating cables-Tolerance andidentification system (Ed.2.0b: 2007)
Thermocouples Part 3:Extension and compensating cables-Tolerance andidentification system
Thermocouples Part 3:Extension and compensating cables-Tolerance andidentification system

DIN
EN
DIN
EN
DIN
EN
JIS

C1610

2012

I.N.

IEC

60584-3

2007

G.B.

BS EN

60584-3

2008

Germany

DIN
EN60584-3

2008

JIS

C 1604

1997

I.N.
USA
G.B.

Germany

Japan

Other

Number

Japan

Japan

Resistancethermometer

SymbolUSA

G.B.

Resistance thermometer sensors

JEM

1252

2000

Platinum resistance thermometer sensors for rotating electrical machines

IEC

60751

2008

SAMA

RC21-4

1966

ASTM

E1137

2004

BS EN

60751

2008

DIN

43760

Deleted

DIN
EN

60751

2009

Industrial platinum resistance thermometer sensors (Amd. 2.Ed2.0b: 2008)
Temperature-resistance values for resistance thermometer element of
platinum, nickel and copperStandard Specification for industrial Platinum Resistance Thermometers
Industrial platinum resistance thermometers and platinum temperature
sensors
Electrical temperature sensors; resistance tables for sensing resistors forresistance elements (Latest: 1987, Move to DIN EN 60751)
Industrial platinum resistance thermometers and platinum temperature
sensorsJIS

Z 87041993

Temperature measurement-electrical methods

JIS

Z 87101993

ASME

PTC 19.3

1974

ASTM

E644

2004

Temperature measurement-general requirement
Part3: Temperature Measurement (instruments and apparatus) reaffirmed
1986Standard test Method for Testing industrial Resistance ThermometersBS

1041-3

1989

Part3: Guide to selection and use of industrial Resistance ThermometersBS

1041-4

1992

Part4: Guide to selection and use of thermocouples

Note: For a certain reason, the standard issue year of this data should also give me as reference the standard which is not owned at our company.

36

OKAZAKI MANUFACTURING COMPANY

TD-1002b

INSTRUCTION MANUAL

CHAPTER 10 CONTACT ADRESS AND PHONE NUMBERS IN CASE OF TROUBLEOKAZAKI MANUFACTURING COMPANY
1-3, Gokodori, 3-Chome, Chuo-Ku, Kobe 651-0087, Japan
Tel : 078-251-8200 Fax : 078-251-8210
OKAZAKI MANUFACTURING COMPANY , TOKYO BRANCH
18-3, Koamicyo, Nihonbashi, Chuo-Ku, Tokyo 103-0016, Japan
Tel : 03-5641-0200 Fax : 03-5641-9100
ARi Industries, Inc., USA

Kiuchi Instrumentation Pte. Ltd.

381 ARi Court, Addison, Ilinois 60101, USA

2 Tuas South Street 3 Singapore 638044

Tel : +1 630 953 9100 Fax : +1 630 953 0590

Tel : +65 6897 7700 Fax : +65 6897 7711

URL : http://www.ariindustries.com

URL : http://www.kiuchi.com.sg

Okazaki Manufacturing (Taiwan) Co., Ltd.

Petroleum Services Co.

1 East 6 Street, KEPZ Kaohsiung, Taiwan ROC

Trade Zone Area - Future Zone, Flamingo Complex

Tel : +886 (0) 7 821 3390 Fax : +886 (0) 7 821 3404

Building 03,

Okazaki Manufacturing Co., European Office

P.O. Box 4098, Safat 13041, Kuwait

Ashwood House, 66 Cardiff Road, Glan-y-Llyn,

Tel : +965 24610801/2/3/16

Taffs Well, Rhondda Cynon Taff CF15 7AF United

Haffar Petroleum Services Co W.L.L

Kingdom

P.O. Box 17152, Doha, Qatar

Tel : +44 (0) 2920 814333

Tel : +974 4415645

URL : http://www.okazaki-mfg.com

Petro Middle East

Kamet trading bv

P.O. Box 802, Abu Dhabi, United Arab Emirates.

Franciscusweg 10-9, 1216 SK Hilversum

Tel : +971 (0) 2 6212140

The Netherlands

ENVIRONMENT Support Co., Ltd.

Tel : +31 35 628 29 10 Fax : +31 35 628 29 12

P.O. Box 9871, Dammam 31423, Kingdom of Saudi

URL : http://www.kamet-trading.nl

ArabiaNewins Co., Ltd.

Tel : +966 569 304056(KOIN B/D #801) 274-8 Youmchang-Dong, Kangseo-Ku,

Dimensions General Enterprises L.L.C.

Seoul, Korea

P.O. Box 595, Postal Code: 326, Oman

Tel : +82 (0) 2 2668 2233 Fax : +82 (0) 2 2668 5100

Tel : +968 9572140

URL : http://www.newins.co.kr

Umicore Marketing Services Australia Pty. Ltd.
Level 5, 606 St. Kilda Rd. Melbourne 3004, Victoria,
Australia
Tel : +61 3 9514 1100 Fax : +61 3 9510 8677
URL : http://www.umicore.com

When you have any troubles concerning the temperature sensors,
contact the above-mentioned address.
URL http://www.okazaki-mfg.com/index.html
E-mail : sales@okazaki-mfg.com

OKAZAKI MANUFACTURING COMPANY

37

TD-1002b

INSTRUCTION MANUALWARRANTY
Our products have cleared proper inspection conducted by us in accordance withthe standards established by our company. Should any irregularity of the Products
take place, however, please contact our branch offices or business officesnearly your places.

PERIOD OF WARRANTY
Period of warranty will be limited to one year from the date of the delivery.
SCOPE OF WARRANTY
Should any irregularity of the Products take place during the foregoing period of
warranty, such Products will be either replaced with new ones or repaired by our
judgment. However, if the irregularity happened due to any of the following,such Products will not be covered by the foregoing warranty.
(1) improper use or handling of the Products(2) any reason irrelevant to the Products(3) remodeling, alteration or repair by other person or company(4) products were the ones manufactured for the purpose of consumption(expendable supply)(5) irregularities of the Products were caused by fire, accident or any othernatural reason such as act of god
In addition, the foregoing warranty is limited to the replacement or repair of the
Products of irregularity and excludes compensation of any other indirect orconsequential damage.

OKAZAKI MANUFACTURING COMPANY

OKAZAKI MANUFACTURING COMPANY

TD-1002b

INSTRUCTION MANUALINSTRUCTION MANUALFOR TEMPERATURE SENSORS
Published by : OKAZAKI MFG. COMPANY
Drawn by : TOKYO TECHNICAL DEPT.
TD-1002Rev.0: Oct.1,1992

TD-1002a Rewrite: Jan.31,2013

Rev.0.3: Aug.12,2013

TD-1002b Rev.1.1: Nov.10,2016

Rev.1.2: Dec.24,2021