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
