1、Designation: E574 13Standard Specification forDuplex, Base Metal Thermocouple Wire With Glass Fiber orSilica Fiber Insulation1This standard is issued under the fixed designation E574; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、 the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification sets forth the requirements for duplex,types E, J, K, N and T thermocouple wire, insul
3、ated withE-glass, S-glass, amorphous silica fiber or polycrystalline fiber.1.2 The values stated in SI units are to be regarded asstandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety problems, if any, associated with its use
4、. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1125 Test Methods for Electrical Conductivity and Resis-tivity of WaterE207
5、 Test Method for Thermal EMF Test of Single Thermo-element Materials by Comparison with a Reference Ther-moelement of Similar EMF-Temperature PropertiesE220 Test Method for Calibration of Thermocouples ByComparison TechniquesE230 Specification and Temperature-Electromotive Force(EMF) Tables for Stan
6、dardized ThermocouplesE344 Terminology Relating to Thermometry and Hydrom-etry3. Terminology3.1 DefinitionsThe definitions given in Terminology E344shall apply to this standard.3.2 Definitions of Terms Specific to This Standard:3.2.1 amorphous silica fiber, ncontinuous filament of heatinsulating mat
7、erial whose principal constituent is amorphoussilica.3.2.2 duplex wire, nmatched pair of parallel, solidthermoelements, individually insulated (double wrap or braid)with insulating fibers and a fiber braid of the same materialoverall.3.2.3 E-glass, nfamily of calcia-alumina-silicate glassesthat are
8、used for general purposes and most electrical applica-tions.3.2.4 impregnate, vto saturate the fiber insulation of wireswith a high-temperature electrical insulating compound to forma moisture barrier around the wires and to inhibit fraying of thefibers.3.2.5 polycrystalline fiber, ncontinuous polyc
9、rystallinefilament of heat insulating material whose composition isalumina, boria, and silica in an approximate ratio of 3:1:2,respectively.3.2.6 S-glass, nfamily of magnesia-alumina-silicateglasses with a higher tensile strength and higher softeningtemperature than E-glass.4. Significance and Use4.
10、1 This specification presents the requirements for impreg-nated and non-impregnated fiber insulated thermocouple wirefor normally accepted industrial use, but does not attempt todefine such usage.4.2 A supplement contains the requirements for insulatedthermocouple wire that will be exposed to high h
11、umidity. Thepurchase order or inquiry shall specify if this supplement isrequired.5. Classification5.1 Class ADuplexE-glass fiber insulated, impregnatedwith a high-temperature electrical insulating compound andcolor coded in accordance with Specification E230.5.2 Class BDuplexE-glass fiber insulated
12、 (Note 1) notimpregnated and not color coded.5.3 Class CDuplexAmorphous silica fiber insulated(Note 2) not impregnated and not color coded.1This specification is under the jurisdiction of ASTM Committee E20 onTemperature Measurement and is the direct responsibility of Subcommittee E20.04on Thermocou
13、ples.Current edition approved May 1, 2013. Published July 2013. Originally approvedin 1976. Last previous edition approved in 2006 as E574 06. DOI: 10.1520/E0574-13.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Bo
14、ok of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.4 Class DDuplexPolycrystalline fiber insulated (Notes2 and 3) not impregnated an
15、d not color coded.5.5 Class EDuplexS-glass fiber insulated, impregnatedwith a high-temperature electrical insulating compound andcolor coded in accordance with Specification E230.5.6 Class FDuplexS-glass fiber insulated (Note 1) notimpregnated and not color coded.NOTE 1May be heat treated to retard
16、fraying when specified inordering information (6.1.8).NOTE 2Fibers may be pre-treated with an organic compound tofacilitate braiding.NOTE 3May be heat cleaned after braiding to remove organiccompound when specified in ordering information (6.1.8).6. Ordering Information6.1 The purchase order shall s
17、pecify the following informa-tion:6.1.1 Total insulated wire length,6.1.2 Thermocouple type,6.1.3 Tolerance on initial values of emf versus temperature(standard or special),6.1.4 Class of insulation (see Section 5),6.1.5 Thermoelement diameter (see 7.1.2),6.1.6 Minimum acceptable continuous length p
18、er spool, ifapplicable,6.1.7 Supplementary testing, if required (see SupplementaryRequirements),6.1.8 Special requirements (if any),6.1.9 Deviations or special requirements not covered herein,and6.1.10 Required documentation (see Section 9).7. Technical Requirements7.1 Insulated Thermocouple Wire:7.
19、1.1 MaterialsThermoelements shall be solid thermo-couple grade materials with a smooth, bright finish (Note 4)and shall be fully annealed prior to insulating.NOTE 4An optional copper-flash coating on the iron thermoelementfor type J thermocouple material is permitted to prevent rusting. Thiscoating
20、must be applied uniformly so that the final calibration tolerancerequirement for the specific insulating material is still met.7.1.2 SizesThermoelements shall be specified in Ameri-can Wire Gage (AWG) nomenclature. Corresponding thermo-element diameters shall be as listed in Table 1.7.1.3 Calibratio
21、n:7.1.3.1 Standard MethodWhen required by the purchaseorder, calibration of the insulated thermocouple wire shall beperformed by one of the procedures described in Test MethodsE207 or E220.7.1.3.2 Thermoelement Initial Calibration TolerancesStandard and special tolerances on initial values of emfver
22、sus temperature are given in Table 1 of Specification E230.The purchase order shall specify whether standard or specialtolerances are required.7.2 Insulation Materials:7.2.1 Individual thermoelements shall be covered with abraid, or double wrap (one wrap in each direction) of glassfibers (Classes A
23、and E), a braid of glass fibers (Classes B andF), or braid of fibers (Classes C and D).7.2.2 The outer covering shall consist of a braid of the samematerial applied over the bare thermoelements.7.2.3 For Classes A and E duplex thermoelements, theinsulation on the individual thermoelements and the ou
24、ter braidshall be impregnated with a moisture and heat-resistant elec-trical insulating compound. The fibers shall be bonded suffi-ciently to each other to prevent fraying under normal condi-tions of installation and service.7.2.4 Each individual ClassAand E thermoelement wrap orbraid and the outer
25、braid shall be color coded in accordancewith Specification E230.7.2.5 The purchase order may specify that an enamelcoating be applied to each bare thermoelement designated asClass A and Class E.7.2.6 Classes B, C, D and F insulated thermoelements aresupplied without impregnation, color coding, or en
26、amel (Notes1-4).7.2.7 Insulating materials shall be suitable for continuoususe to the temperatures listed in Table 2.7.2.8 The amount of insulation coverage affects the durabil-ity and abrasion resistance of the insulating material. Applica-tion conditions should be discussed with the manufacturer t
27、oaddress these needs.7.3 Dimensions and Finish:7.3.1 The maximum outside transverse dimension as shownin Fig. 1, including outer covering of insulated duplex thermo-couple wire, shall not exceed the dimensions given in Table 1.7.3.2 The duplex insulated thermocouple wire shall becapable of being wou
28、nd around a mandrel having a diameter ofTABLE 1 Maximum Outside Transverse Dimensions of InsulatedWireUninsulated ThermoelementDiameterMaximum Outside DimensionsGage(AWG)NominalDiameterClasses A, B, E andFClasses C and Dmm (in.) mm (in.) mm (in.)20 0.8 (0.032) 2.7 (0.105) 4.5 (0.180)22 0.6 (0.025) 2
29、.3 (0.090) 4.1 (0.160)24 0.5 (0.020) 2.1 (0.080) 3.8 (0.150)30 0.3 (0.010) 1.7 (0.065) noneTABLE 2 Maximum Recommended Continuous UseTemperatures for Insulating MaterialsMaterials Temperature CommentEnamels andimpregnants200C (400F) May be used to 500C (930F) withdecomposition and color loss inhot z
30、oneE-Glass fibers (notimpregnated)340C (650F) Retains 75 % of tensile strength,softens at 730C (1350F)S-Glass fibers (notimpregnated)395C (750F) Retains 80 % of tensile strength,softens at 850C (1560F)Amorphous silicafibers (notimpregnated)980C (1800F) NonePolycrystalline fibers(not impregnated)1250
31、C (2200F) NoneE574 1321.5 times the maximum outside dimension (Table 1) withoutcracking or fracturing of the insulation to an extent visible tothe unaided eye.8. Packaging and Package Marking8.1 The insulated thermocouple wire shall be packaged forshipment in containers that will protect it from phy
32、sicaldamage and moisture.8.2 The insulated thermocouple wire shall be wound onspools, one continuous length per spool. The purchase ordershall specify accessibility of the inner 3 m (10 ft) of insulatedwire on the spool, when required by the user.8.3 The minimum spool core diameter for fiber insulat
33、edduplex thermocouple wire shall be 50 mm (2 in.).8.4 Spools or inner packaging shall be marked plainly withthe following:8.4.1 Thermocouple type,8.4.2 Thermoelement diameter,8.4.3 ASTM specification and insulation class,8.4.4 Manufacturers name,8.4.5 Length of wire on spool, and8.4.6 Thermoelectric
34、 tolerance (standard or special).9. Quality Assurance Procedure9.1 This specification recognizes the need of quality assur-ance and control of product being supplied. The level of qualityassurance requirements, enforcement, and documentation mustbe determined by the application and specified in the
35、purchas-ing documents. Table 3 lists the tests which shall be performedon the specific lot of insulated wire furnished, when specifiedin the purchase order:9.1.1 The absence of specified testing does not relieve themanufacturer of the responsibility to supply material meetingthe technical requiremen
36、ts of this specification (excludingSupplementary Requirement S1). The manufacturer may per-form any of the listed tests and any other test deemed necessaryto ensure the quality of the material. The user may perform anyof the listed tests (see above) as the basis of acceptance.9.2 The test covered by
37、 Supplementary Requirement S1shall be performed by the manufacturer when specified in thepurchase document.9.3 The manufacturer shall supply the following whenspecified in the purchase document:9.3.1 A statement of compliance certifying that all materialsupplied is in accordance with this specificat
38、ion, and9.3.2 The results of specified tests.10. Keywords10.1 amorphous silica fiber insulated wire; duplex insulatedthermocouple wire; glass fiber insulated wire; glass insulatedthermocouple wire; insulated thermocouple wire; polycrystal-line fiber insulated wire; thermocouple wireSUPPLEMENTARY REQ
39、UIREMENTSThe following supplementary requirements shall apply only when specified by the purchaser in theinquiry or purchase order.S1. Resistance TestS1.1 The finished Classes A and E duplex insulated wireshall be capable of passing the following wet insulationresistance test (Note S1):Asample of wi
40、re at least 300 mm (12in.) long shall be bent at its center 180 around a 13 mm (12 in.)diameter mandrel to form a U-shaped loop with straight sides.S1.2 The loop shall be immersed to a depth of 50 mm 6 6mm (2 in. 614 in.) in 25 C 6 2 C (77 F 6 4 F) waterhaving a resistivity (Note S2) of not more tha
41、n 1 103-cmfor at least 10 min.NOTE S1The purchasing document may specify an alternate wetFIG. 1 Transverse DimensionTABLE 3 Tests to be Performed when Specified in the PurchaseOrderTest ParagraphSize Verification 7.1.2, 7.3.1, 8.3Calibration 7.1.3Insulation Quality 7.3.2E574 133insulation resistance
42、 test which has been agreed upon by the purchaser andthe manufacturer.NOTE S2The resistivity of water shall be determined in accordancewith Test Methods D1125.S1.3 The wet insulation resistance will be acceptable if thecurrent is less than 50 Awhen 180 V dc is impressed betweenthe thermoelements or
43、a megohmeter meter measures morethan 3.6 106 resistance when a minimum of 200 V dc isimpressed between the thermoelements.S2. Precision and BiasS2.1 Wet insulation resistance measurement in the supple-mentary requirement is primarily used to determine the mois-ture resistance of the insulated thermo
44、couple wire over aspecified arbitrary time period. Both parties should concur as tothe sampling procedure prior to undertaking this pass or failtest. Consequently, statements of precision and bias are notrelevant.ASTM International takes no position respecting the validity of any patent rights asser
45、ted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by
46、the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receiv
47、e careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM Intern
48、ational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).E574 134
