1、Designation: E839 11 (Reapproved 2016)1Standard Test Methods forSheathed Thermocouples and Sheathed ThermocoupleCable1This standard is issued under the fixed designation E839; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r 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.1NOTEAdded references to Tables X1.7 and X1.8 to 10.7.4 editorially in December 2016.1. Scope1.1 This document lists methods
3、for testing Mineral-Insulated, Metal-Sheathed (MIMS) thermocouple assembliesand thermocouple cable, but does not require that any of thesetests be performed nor does it state criteria for acceptance. Theacceptance criteria are given in other ASTM standard specifi-cations that impose this testing for
4、 those thermocouples andcable. Examples from ASTM thermocouple specifications foracceptance criteria are given for many of the tests. Thesetabulated values are not necessarily those that would berequired to meet these tests, but are included as examples only.1.2 These tests are intended to support q
5、uality control and toevaluate the suitability of sheathed thermocouple cable orassemblies for specific applications. Some alternative testmethods to obtain the same information are given, since in agiven situation, an alternative test method may be morepractical. Service conditions are widely variab
6、le, so it isunlikely that all the tests described will be appropriate for agiven thermocouple application. A brief statement is madefollowing each test description to indicate when it might beused.1.3 The tests described herein include test methods tomeasure the following properties of sheathed ther
7、mocouplematerial and assemblies.1.3.1 Insulation Properties:1.3.1.1 Compactiondirect method, absorption method,and tension method.1.3.1.2 Thickness.1.3.1.3 Resistanceat room temperature and at elevatedtemperature.1.3.2 Sheath Properties:1.3.2.1 Integritytwo water test methods and mass spec-trometer.
8、1.3.2.2 Dimensionslength, diameter, and roundness.1.3.2.3 Wall thickness.1.3.2.4 Surfacegross visual, finish, defect detection bydye penetrant, and cold-lap detection by tension test.1.3.2.5 Metallurgical structure.1.3.2.6 Ductilitybend test and tension test.1.3.3 Thermoelement Properties:1.3.3.1 Ca
9、libration.1.3.3.2 Homogeneity.1.3.3.3 Drift.1.3.3.4 Thermoelement diameter, roundness, and surfaceappearance.1.3.3.5 Thermoelement spacing.1.3.3.6 Thermoelement ductility.1.3.3.7 Metallurgical structure.1.3.4 Thermocouple Assembly Properties:1.3.4.1 Dimensionslength, diameter, and roundness.1.3.4.2
10、Surfacegross visual, finish, reference junction endmoisture seal, and defect detection by dye penetrant.1.3.4.3 Electricalcontinuity, loop resistance, and connec-tor polarity.1.3.4.4 Radiographic inspection.1.3.4.5 Thermoelement diameter.1.3.4.6 Thermal response time.1.3.4.7 Thermal cycle.1.4 The va
11、lues stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standa
12、rd.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. 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.1These test
13、methods are under the jurisdiction of ASTM Committee E20 onTemperature Measurement and is the direct responsibility of Subcommittee E20.04on Thermocouples.Current edition approved Nov. 1, 2011. Published January 2016. Originallyapproved in 1989. Last previous edition approved in 2011 as E839 11. DOI
14、:10.1520/E0839-11R16E01.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for
15、 theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organiziation Technical Barriers to Trade (TBT) Committee.12. Referenced Documents2.1 ASTM Standards:2E3 Guide for Preparation of Metallographic SpecimensE94 Guide for Radiographic ExaminationE112 Test M
16、ethods for Determining Average Grain SizeE165 Practice for Liquid Penetrant Examination for GeneralIndustryE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE207 Test Method for Thermal EMF Test of Single Thermo-element Materials by Comparison with a Reference Ther-moelement o
17、f Similar EMF-Temperature PropertiesE220 Test Method for Calibration of Thermocouples ByComparison TechniquesE230 Specification and Temperature-Electromotive Force(EMF) Tables for Standardized ThermocouplesE235 Specification for Thermocouples, Sheathed, Type Kand Type N, for Nuclear or for Other Hig
18、h-ReliabilityApplicationsE344 Terminology Relating to Thermometry and Hydrom-etryE585/E585M Specification for Compacted Mineral-Insulated, Metal-Sheathed, Base Metal ThermocoupleCableE608/E608M Specification for Mineral-Insulated, Metal-Sheathed Base Metal ThermocouplesE691 Practice for Conducting a
19、n Interlaboratory Study toDetermine the Precision of a Test MethodE780 Test Method for Measuring the Insulation Resistanceof Mineral-Insulated, Metal-Sheathed Thermocouples andThermocouple Cable at Room TemperatureE1025 Practice for Design, Manufacture, and MaterialGrouping Classification of Hole-Ty
20、pe Image Quality In-dicators (IQI) Used for RadiologyE1129/E1129M Specification for Thermocouple ConnectorsE1350 Guide for Testing Sheathed Thermocouples, Thermo-couples Assemblies, and Connecting Wires Prior to, andAfter Installation or ServiceE1684 Specification for Miniature Thermocouple Connec-t
21、orsE1751 Guide for Temperature Electromotive Force (EMF)Tables for Non-Letter Designated Thermocouple Combi-nations (Withdrawn 2009)3E2181/E2181M Specification for Compacted Mineral-Insulated, Metal-Sheathed, Noble Metal Thermocouplesand Thermocouple Cable2.2 ANSI StandardB 46.1 Surface Texture42.3
22、Other StandardUSAEC Division of Reactor Development and TechnologyRDT Standard C 2-1T Determination of Insulation Com-paction in Ceramic Insulated Conductors August 19703. Terminology3.1 DefinitionsThe definitions given in Terminology E344shall apply to these test methods.3.2 Definitions of Terms Sp
23、ecific to This Standard:3.2.1 bulk cable, na single length of thermocouple cableproduced from the same raw material lots after completion offabrication.3.2.2 cable lot, na quantity of finished mineralinsulated,metal-sheathed thermocouple cable manufactured from tubingor other sheath material from th
24、e same heat, wire from thesame spool and heat, and insulation from the same batch, thenassembled and processed together under controlled productionconditions to the required final outside diameter.3.2.3 cold-lap, nsheath surface defect where the sheathsurface has been galled and torn by a drawing di
25、e and the tornsurface smoothed by a subsequent diameter reduction.3.2.4 insulation compaction density, nthe density of acompacted powder is the combined density of the powderparticles and the voids remaining after the powder compaction.Sometimes the insulation compaction density is divided by thethe
26、oretical density of the powder particles to obtain a dimen-sionless fraction of theoretical density as a convenient methodto express the relative compaction.3.2.5 raw material, ntubing or other sheath material,insulation and wires used in the fabrication of sheathedthermocouple cable.3.2.6 short ran
27、ge ordering, nthe reversible short-ranged,order-disorder transformation in which the nickel and chro-mium atoms occupy specific (ordered) localized sites in theType EP or Type KP thermoelement alloy crystal structure.3.2.7 thermal response time, nthe time required for asheathed thermocouple signal t
28、o attain the specified percent ofthe total voltage change produced by a step change oftemperature at the sheaths outer surface.4. Summary of Test Methods4.1 Insulation Properties:4.1.1 CompactionThese tests ensure that the insulation iscompacted sufficiently (1) to prevent the insulation fromshiftin
29、g during use with the possibility of the thermoelementsshorting to each other or to the sheath, and (2) to have goodheat transfer between the sheath and the thermoelements.4.1.2 Insulation ResistanceThe insulation shall be free ofmoisture and contaminants that would compromise thevoltage-temperature
30、 relationship or shorten the useful life ofthe sheathed thermocouple. Measurement of insulation resis-tance is a useful way to detect the presence of unacceptablelevels of impurities in the insulation.4.2 Sheath Properties:4.2.1 IntegrityThese tests ensure that (1) the sheath willbe impervious to mo
31、isture and gases so the insulation andthermoelements will be protected, (2) surface flaws and cracksthat might develop into sheath leaks are detected, and (3) thesheath walls are as thick as specified.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Servi
32、ce at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.
33、,4th Floor, New York, NY 10036.E839 11 (2016)124.2.2 DimensionsDetermination of length, diameter, andsheath roundness are often necessary to assure proper dimen-sional fit.4.2.3 Sheath DuctilityThe sheath shall be ductile enoughto bend the required amount without breaking or cracking.4.3 Thermoeleme
34、nt Properties Service Life:4.3.1 CalibrationThis test ensures that the temperature-emf relationship initially corresponds to standardized toler-ances.4.3.2 SizeThe thermocouple sheath and thermoelementsizes are related to the service life and the thermoelementspacing is related to possible low insul
35、ation resistance orshorting.4.3.3 Thermoelement DuctilityDuctility of the thermoele-ments shall be sufficient to allow the assembly to be bentduring assembly or service without significant damage to thethermoelements.4.4 Thermocouple Assembly PropertiesThe criteria listedabove shall apply to both th
36、ermocouple assemblies and to bulkcable. In addition, the following tests are important forthermocouple assemblies.4.4.1 ContinuityThe loop continuity test assures that thethermocouple assembly has a completed circuit.4.4.2 Loop ResistanceThe loop resistance test can detectshorted or damaged thermoel
37、ements.4.4.3 PolarityThe connector polarity test indicateswhether the connector is correctly installed.4.4.4 Moisture SealThe moisture seal at the referencejunction end of the thermocouple, if faulty, may allow con-tamination of the insulation with moisture or gases.4.4.5 RadiographyRadiographic exa
38、mination of the junc-tion and sheath closure weld can indicate faulty junctions andsheath closures that will lead to early failure. Most internaldimensions can also be measured from the radiograph.4.4.6 Response TimeThe thermal response time gives anindication of the quickness with which an installe
39、d thermo-couple will signal a changing temperature under the testconditions.4.4.7 Thermal CycleThe thermal cycle test will offerassurance that the thermocouple will not have early failurebecause of strains imposed from temperature transients.5. Significance and Use5.1 This standard provides a descri
40、ption of test methodsused in other ASTM specifications to establish certain accept-able limits for characteristics of thermocouple assemblies andthermocouple cable. These test methods define how thosecharacteristics shall be determined.5.2 The usefulness and purpose of the included tests aregiven fo
41、r the category of tests.5.3 WarningUsers should be aware that certain charac-teristics of thermocouples might change with time and use. Ifa thermocouples designed shipping, storage, installation, oroperating temperature has been exceeded, that thermocouplesmoisture seal may have been compromised and
42、 may no longeradequately prevent the deleterious intrusion of water vapor.Consequently, the thermocouples condition established by testat the time of manufacture may not apply later. In addition,inhomogeneities can develop in thermoelements because ofexposure to higher temperatures, even in cases wh
43、ere maxi-mum exposure temperatures have been lower than the sug-gested upper use temperature limits specified in Table 1 ofSpecification E608/E608M. For this reason, calibration ofthermocouples destined for delivery to a customer is notrecommended. Because the EMF indication of any thermo-couple dep
44、ends upon the condition of the thermoelementsalong their entire length, as well as the temperature profilepattern in the region of any inhomogeneity, the EMF output ofa used thermocouple will be unique to its installation. Becausetemperature profiles in calibration equipment are unlikely toduplicate
45、 those of the installation, removal of a used thermo-couple to a separate apparatus for calibration is not recom-mended. Instead, in situ calibration by comparison to a similarthermocouple known to be good is often recommended.6. General Requirements6.1 All the inspection operations are to be perfor
46、med underclean conditions that will not degrade the insulation, sheath, orthermoelements. This includes the use of suitable gloves whenappropriate.6.2 During all process steps in which insulation is exposedto ambient atmosphere, the air shall be clean, with less than50 % relative humidity, and at a
47、temperature between 20 and26C (68 and 79F).6.3 All samples which are tested shall be identified bymaterial code, and shall be traceable to a production run.7. Insulation Properties7.1 Insulation Compaction DensityThe thermal conduc-tivity of the insulation, as well as the ability of the insulation t
48、olock the thermoelements into place, will be affected by theinsulation compaction density.7.1.1 A direct method for measuring insulation compactiondensity is applicable if a representative sample can be sec-tioned so that the sample ends are perpendicular to the samplelength and the sheath, thermoel
49、ements, and insulation form asmooth surface free of burrs. The procedure is as follows:7.1.1.1 Weigh the sample section,7.1.1.2 Measure the sheath diameter and length with amicrometer,7.1.1.3 Separate the insulation from the thermoelement andsheath with the use of an air abrasive tool,7.1.1.4 Weigh the thermoelements and sheath, and7.1.1.5 Determine the sheath and thermoelements densitieseither by experiment or from references.7.1.1.6 Determine the percentage of the maximum theoreti-cal insulation density as follows:% 5 100A 2 B!/$0
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