Thermocouple Wire
A thermocouple is a temperature measuring device consisting of two conductors of dissimilar metals or alloys that are connected only at the ends. When the ends are at different temperatures a small voltage is produced in the wire that can be related directly to the temperature difference between the ends. If the temperature at one end is known, the temperature at the other end can be determined.
Thermocouple wire or extension grade wire is recommended to be used to connect thermocouples to the sensing or control instrumentation. The conditions of measurement determine the type of thermocouple wire and insulation to be used. Temperature range, environment, insulation requirements, response, and service life should be considered.
Calibration Type Characteristics

TYPE J (Iron vs Constantan) is used in vacuum, oxidizing, inert or reducing atmospheres.
Iron element oxidizes rapidly at temperatures exceeding 538'C, and therefore heavier gauge
wire is recommended for longer life at these temperatures.
TYPE K (CHROMEL vs ALUMEL ) is used in oxidizing, inert or dry reducing atmospheres.
Exposure to vacuum limited to short time periods. Must be protected from sulfurous and marginally
oxidizing atmospheres. Reliable and accurate at high temperatures.
TYPE T (Copper vs Constantan) is used or service in oxidizing, inert or reducing atmospheres or in
vacuum. It is highly resistant to corrosion from atmospheric moisture and condensation and exhibits
high stability at low temperatures. It is the only type with limits of error guaranteed for cryogenic temperatures.
TYPE E (CHROMEL vs Constantan) may be used in oxidizing, inert or dry reducing atmospheres, or for short
periods of time under vacuum. Must be protected from sulfurous and marginally oxidizingatmospheres.
Produces the highest EMF per degree o any standardized thermocouple.

Abbreviations
AMS           Aerospace Material Specification
ANSI          American National Standard Institute
ASTM        American Society of Testing and Materials
BAC           Boeing Aircraft Corporation
CSA           Canadian Standards http://www.aesirautomation.com
IEC            International Electrotechnical Commission
IEEE         Institute of Electrical and Electronic Engineers
ISO            International Standards Organization
MIL STD Military Standard
NCSL        National Conference of Standard Laboratories
NEC          National Electrical Code
UL             Underwriters Laboratories
Specifications
AMS 2750                     Pyrometry
ANSI MC96.1               Temperature Measurement Thermocouples
ANSI/NCSL Z540-1    Calibration Laboratories and Measuring and Test Equipment General Requirements
ASTM E207                 Thermal EMF Test of Single Thermoelement Materials
ASTM E 220                Calibration of Thermocouples by Comparison Techniques
ASTM E 230                Standard Specification and EMF Tables for Standardized Thermocouples
BAC-5621                    Temperature Control For Processing Materials
CSA-C22.2 No. 239     Control and Instrumentation Cable
IEC 584                        Thermocouples http://www.siaminstrument.com
IEEE 383                      Standard Test for Class 1E Cables for Nuclear Generation Stations
IS0 Guide 25                General Requirements for the Competence of Calibration and Testing Laboratories
ISO 9001-2000             ISO 9001-2000 Quality Management
MIL-STD-105             Sampling Procedures and Tables for Inspection by Attributes
MIL-STD-45662A      Calibration System Requirements
NEC Article 340         Power and Control Tray Cable
NEC Article 501         Class 1 Locations http://www.ies-thailand.com
NEC Article 725         Instrumentation Tray Cable
NEC Article 727         Power-Limited Circuit Cable
UL 13                          Power-Limited Circuit Cable
UL 62                          Flexible Cord and Fixture Wire
UL 83                          Thermoplastic-Insulated Wires and Cables
UL 1277                      Electrical Power and Control Tray Cables
UL 1581                      Reference Standard for Electrical Wires, Cables, and Flexible Cords
UL 2250                      Instrumentation Tray Cable

Properties of Insulating and Jacketing Materials

Material Type

Continuous
Operating
Temperature

Abrasion Resistance

Chemical Resistance

Moisture Resistance

Solvent Resistance

Flame Resistance

PE

80°C

Good

Excellent

Excellent

Excellent

Poor

CPE

90°C

Very Good

Excellent

Excellent

Excellent

Excellent

PVC

105°C

Very Good

Very Good

Good

Fair

Excellent

TPE

125°C

Excellent

Poor

Good

Good

Excellent

Nylon

121°C

Excellent

Very Good

Fair

Good

Poor

ETFE

150°C

Excellent

Excellent

Excellent

Excellent

Excellent

FEP

200°C

Excellent

Excellent

Excellent

Excellent

Excellent

TE/D

200°C

Excellent

Excellent

Excellent

Excellent

Excellent

PFA

260°C

Excellent

Excellent

Excellent

Excellent

Excellent

PTFE

260°C

Good

Excellent

Excellent

Excellent

Excellent

Polyimide

260°C

Excellent

Excellent

Excellent

Good

Good

B-Fiber*

260°C

Good

Good

Fiar

Good

Good

G-Glass*

510°C

Poor

Good

Good

Excellent

Excellent

Q-Glass*

704°C

Fair

Good

Good

Excellent

Excellent

HG

982°C

Poor

Good

Poor

Excellent

Excellent

CEFIR(TM)

1204°C

Fair

Good

Fair

Excellent

Excellent

Standard Wire Data

A.W.G Size

Stranding

Approx. O.D.

A.W.G Size

Stranding

Approx. O.D.

30

7/38

.012

16

7/24

.060

30

19/42

.012

16

19/29

.058

28

7/36

.015

14

7/22

.073

28

19/40

.016

14

19/27

.076

26

7/34

.019

12

7/20

.096

26

19/38

.020

12

19/25

.093

24

7/32

.024

10

37/26

.110

24

19/36

.024

10

105/30

.111

24

7/30

.030

8

133/29

.161

22

19/34

.031

6

133/27

.202

20

7/28

.037

4

133/25

.255

20

/19/32

.037

2

665/30

.331

18

7/26

.048

-

-

-

18

19/30

.050

-

-

-

Metric Conversion Chart

		Stranded		Diameter
AWG Size	MM*	N x OD inches	MM	Inches	MM
10	5.3	1 x .102 7 x .0385	2.59 .978	.102 .116	2.59 2.95
	4.0	1 x .089 7 x .0335	2.26 .850	.089 .100	2.26 2.55
12	3.32	1 x .081 7 x .032	2.05 .813	.081 .096	2.05 2.44
	2.5	1 x .070 7 x .0266	1.78 .670	.070 .080	1.78 2.01
14	2.07	1 x .064 7 x .0253	1.63 .635	.064 .076	1.63 1.93
	1.5	1 x .054 7 x .0206	1.38 .520	.054 .063	1.38 1.57
16	1.32	1 x .051 7 x .0201	1.29 .511	.051 .060	1.29 1.53
	1.0	1 x .045 7 x .0169	1.13 .430	.045 .051	1.13 1.30
18	.812	1 x .0407 x .0159 19 x .010	1.02 .406 .254	.040 .048 .050	1.02 1.22 1.27
	.75	1 x .039 7 x .0146	1.00 .370	.039 .044	1.00 1.11
20	.52	1 x .032 7 x .0126	.813 .320	.032 .038	.813 .970
	.50	1 x .03157 x .0118	.800 .300	.0315 .035	.800 .900
22	.325	1 x .0257 x .010	.635 .254	.0253 .030	.635 .790
24	.205	1 x .020 7 x .008	.511 .203	.0201 .024	.511 .610
26	.128	1 x .0159	.406	.0159	.406
28	.080	1 x .0126	.320	.0126	.320
30	.051	1 x .010	.254	.010	.254
32	.032	1 x 008	.203	.008	.203
34	.020	1 x .0063	.160	.0063	.160
36	.013	1 x. 005	.127	.005	.127

Colour Codes

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