ASTM E574-00

Standard Specification for Duplex, Base Metal Thermocouple Wire With Glass Fiber or Silica Fiber Insulation

SCOPE
1.1 This specification sets forth the requirements for duplex, types E, J, K, N and T thermocouple wire, insulated with E-glass, S-glass, amorphous silica fiber or polycrystalline fiber.
1.2 The values stated in either inch-pound units or SI units are to be regarded separately as standard. They may not be exact equivalents, but either may be used as given.  
1.3 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-May-2000
• ICS: 17.200.20 - Temperature-measuring instruments
• Technical Committee: E20 - Temperature Measurement

Relations

• Replaced By: ASTM E574-06 - Standard Specification for Duplex, Base Metal Thermocouple Wire With Glass Fiber or Silica Fiber Insulation
• Effective Date: 01-May-2006
• Referred By: ASTM E230/E230M-17 - Standard Specification for Temperature-Electromotive Force (emf) Tables for Standardized Thermocouples
• Effective Date: 10-May-2000
• Referred By: ASTM E633-21a - Standard Guide for Use of Thermocouples in Elevated-Temperature Mechanical Testing
• Effective Date: 10-May-2000
• Referred By: ASTM E344-20 - Terminology Relating to Thermometry and Hydrometry
• Effective Date: 10-May-2000

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E 574 – 00
Standard Specification for
Duplex, Base Metal Thermocouple Wire With Glass Fiber or
Silica Fiber Insulation
This standard is issued under the fixed designation E 574; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3.2.1 amorphous silica fiber, n—a continuous filament of
heat insulating material whose principal constituent is amor-
1.1 This specification sets forth the requirements for duplex,
phous silica.
types E, J, K, N and T thermocouple wire, insulated with
3.2.2 duplex wire, n—a matched pair of parallel, solid
E-glass, S-glass, amorphous silica fiber or polycrystalline fiber.
thermoelements, individually insulated (double wrap or braid)
1.2 The values stated in either SI units or inch-pound units
with insulating fibers and a fiber braid of the same material
are to be regarded separately as standard. They may not be
overall.
exact equivalents, but either may be used as given.
3.2.3 E-glass, n—a family of calcia-alumina-silicate glasses
1.3 This standard does not purport to address all of the
that are used for general purposes and most electrical applica-
safety problems, if any, associated with its use. It is the
tions.
responsibility of the user of this standard to establish appro-
3.2.4 impregnate, vt—to saturate the fiber insulation of
priate safety and health practices and determine the applica-
wires with a high-temperature electrical insulating compound
bility of regulatory limitations prior to use.
to form a moisture barrier around the wires and to inhibit
2. Referenced Documents fraying of the fibers.
3.2.5 polycrystalline fiber, n—a continuous polycrystalline
2.1 ASTM Standards:
filament of heat insulating material whose composition is
D 1125 Test Methods for Electrical Conductivity and Re-
alumina, boria, and silica in an approximate ratio of 3:1:2,
sistivity of Water
respectively.
E 207 Test Method for Thermal EMF Test of Single-
3.2.6 S-glass, n—a family of magnesia-alumina-silicate
ThermoelementMaterialsbyComparisonwithaReference
glasses with a higher tensile strength and higher softening
Thermoelement of Similar Emf-Temperature Properties
temperature than E-glass.
E 220 Test Method for Calibration of Thermocouples by
Comparison Techniques
4. Significance and Use
E 230 Specification and Temperature-Electromotive Force
3 4.1 This specification presents the requirements for impreg-
(Emf) Tables for Standardized Thermocouples
nated and non-impregnated fiber insulated thermocouple wire
E 344 Terminology Relating to Thermometry and Hydrom-
3 for normally accepted industrial use, but does not attempt to
etry
define such usage.
3. Terminology 4.2 A supplement contains the requirements for insulated
thermocouple wire that will be exposed to high humidity. The
3.1 Definitions—The definitions given in Terminology
purchase order or inquiry shall specify if this supplement is
E 344 shall apply to this standard.
required.
3.2 Definitions of Terms Specific to This Standard:
5. Classification
1 5.1 Class A–Duplex—E-glass fiber insulated, impregnated
This specification is under the jurisdiction of ASTM Committee E20 on
with a high-temperature electrical insulating compound and
Temperature Measurement and is the direct responsibility of Subcommittee E20.04
on Thermocouples.
color coded in accordance with ANSI/ASTM Specification
Current edition approved May 10, 2000. Published August 2000. Originally
E 230.
published as E 574–76. Last previous edition E 574–93.
5.2 Class B–Duplex—E-glass fiber insulated (Note 1) not
Annual Book of ASTM Standards, Vol 11.01.
Annual Book of ASTM Standards, Vol 14.03. impregnated and not color coded.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E 574
5.3 Class C–Duplex—Amorphous silica fiber insulated 7.1.3.1 Standard Method—When required by the purchase
(Note 2) not impregnated and not color coded. order, calibration of the insulated thermocouple wire shall be
5.4 Class D–Duplex—Polycrystalline fiber insulated (Notes performed by one of the procedures described in Test Method
2 and 3) not impregnated and not color coded. E 207 or Test Method E 220.
5.5 Class E–Duplex—S-glass fiber insulated, impregnated
7.1.3.2 Thermoelement Initial Calibration Tolerances—
with a high-temperature electrical insulating compound and Standard and special tolerances on initial values of emf versus
color coded in accordance with ANSI/ASTM Specification
temperature are given in Table 1 ofANSI/ASTM Specification
E 230. E 230. The purchase order shall specify whether standard or
5.6 Class F–Duplex—S-glass fiber insulated (Note 1) not
special tolerances are required.
impregnated and not color coded.
7.2 Insulation Materials:
7.2.1 Individual thermoelements shall be covered with a
NOTE 1—May be heat treated to retard fraying when specified in
braid, or double wrap (one wrap in each direction) of glass
ordering information (6.1.8).
NOTE 2—Fibers may be pre-treated with an organic compound to fibers (ClassesAand E), a braid of glass fibers (Classes B and
facilitate braiding.
F), or braid of fibers (Classes C and D).
NOTE 3—May be heat cleaned after braiding to remove organic
7.2.2 The outer covering shall consist of a braid of the same
compound when specified in ordering information (6.1.8).
material applied over the bare thermoelements.
7.2.3 For Classes A and E duplex thermoelements, the
6. Ordering Information
insulationontheindividualthermoelementsandtheouterbraid
6.1 The purchase order shall specify the following informa-
shall be impregnated with a moisture and heat-resistant elec-
tion:
trical insulating compound. The fibers shall be bonded suffi-
6.1.1 Total insulated wire length,
ciently to each other to prevent fraying under normal condi-
6.1.2 Thermocouple type,
tions of installation and service.
6.1.3 Tolerance on initial values of emf versus temperature
7.2.4 Each individual ClassAand E thermoelement wrap or
(standard or special),
braid and the outer braid shall be color coded in accordance
6.1.4 Class of insulation,
with ANSI/ASTM Specification E 230.
6.1.5 Thermoelement diameter,
7.2.5 The purchase order may specify that an enamel
6.1.6 Minimum acceptable continuous length per spool, if
coating be applied to each bare thermoelement designated as
applicable,
Class A and Class E.
6.1.7 Supplementary testing, if required (see Supplementary
7.2.6 Classes B, C, D and F insulated thermoelements are
Requirements),
supplied without impregnation, color coding, or enamel (Notes
6.1.8 Special requirements (if any),
1-4).
6.1.9 Deviations or special requirements not covered herein,
7.2.7 Insulating materials shall be suitable for continuous
and
use to the temperatures listed in Table 2.
6.1.10 Required documentation (see Section 9).
7.2.8 The amount of insulation coverage affects the durabil-
ity and abrasion resistance of the insulating material. Applica-
7. Technical Requirements
tion conditions should
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