1、Designation: E2181/E2181M 11Standard Specification forCompacted Mineral-Insulated, Metal-Sheathed, Noble MetalThermocouples and Thermocouple Cable1This standard is issued under the fixed designation E2181/E2181M; the number immediately following the designation indicates the yearof original adoption
2、 or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification establishes dimensional and materialrequirements for comp
3、acted, mineral-insulated, metal-sheathed(MIMS), Type S (platinum-10 % rhodium versus platinum),Type R (platinum-13 % rhodium versus platinum), and Type B(platinum-30 % rhodium versus platinum-6 % rhodium) noblemetal thermocouples. This specification also establishes di-mensional and material require
4、ments for compacted MIMScable with at least one noble metal thermoelement pair.1.2 This specification describes both the required processingand testing requirements and also the optional supplementarytesting and quality assurance requirements.1.3 Provisions are made for selecting the type of nobleme
5、tal thermocouple or thermoelements, either magnesia(MgO) or alumina (Al2O3) insulation, and a noble metal alloyor other alternate heat-resistant sheath material. Provisions arealso made for selecting a thermocouple measuring junctionstyle and for a transition or termination.1.4 The values stated in
6、inch-pound units or SI (metric)units may be regarded separately as standard. The values statedin each system are not the exact equivalents, and each systemshall be used independently of the other.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use
7、. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory requirements prior to use.2. Referenced Documents2.1 The following documents of the latest issue form a partof this specification to the extent
8、specified herein. In the eventof a conflict between this specification and other specificationsreferenced herein, this specification shall take precedence.2.2 ASTM Standards:2A213/A213M Specification for Seamless Ferritic and Aus-tenitic Alloy-Steel Boiler, Superheater, and Heat-Exchanger TubesA249/
9、A249M Specification for Welded Austenitic SteelBoiler, Superheater, Heat-Exchanger, and CondenserTubesA269 Specification for Seamless and Welded AusteniticStainless Steel Tubing for General ServiceA632 Specification for Seamless and Welded AusteniticStainless Steel Tubing (Small-Diameter) for Genera
10、l Ser-viceB163 Specification for Seamless Nickel and Nickel Alloy(UNS N06845) Condenser and Heat-Exchanger TubesB167 Specification for Nickel-Chromium-Iron Alloys(UNS N06600, N06601, N06603, N06690, N06693,N06025, N06045, and N06696), Nickel-Chromium-Cobalt-Molybdenum Alloy (UNS N06617), and Nickel-
11、Iron-Chromium-Tungsten Alloy (UNS N06674) SeamlessPipe and TubeB516 Specification for Welded Nickel-Chromium-Iron Al-loy (UNS N06600, UNS N06603, UNS N06025, and UNSN06045) TubesE165 Practice for Liquid Penetrant Examination for GeneralIndustryE220 Test Method for Calibration of Thermocouples ByComp
12、arison TechniquesE230 Specification and Temperature-Electromotive Force(EMF) Tables for Standardized ThermocouplesE344 Terminology Relating to Thermometry and Hydrom-etryE608/E608M Specification for Mineral-Insulated, Metal-Sheathed Base Metal ThermocouplesE839 Test Methods for Sheathed Thermocouple
13、s andSheathed Thermocouple CableE1652 Specification for Magnesium Oxide and AluminumOxide Powder and Crushable Insulators Used in the1This specification is under the jurisdiction of ASTM Committee E20 onTemperature Measurement and is the direct responsibility of Subcommittee E20.04on Thermocouples.C
14、urrent edition approved Nov. 1, 2011. Published December 2011. Originallyapproved in 2001. Last previous edition approved in 2006 as E2181/E2181M 06E01. DOI: 10.1520/E2181_E2181M-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.o
15、rg. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Manufacture of Metal-Sheathed Platinum Resistance Ther-mometers,
16、 Base Metal Thermocouples, and Noble MetalThermocouplesE1751/E1751M Guide for Temperature ElectromotiveForce (emf) Tables for Non-Letter Designated Thermo-couple Combinations2.3 ANSI Standard:3B46.1 Surface Texture3. Terminology3.1 DefinitionsThe definitions given in TerminologyE344 shall apply to t
17、his specification.3.2 Definitions of Terms Specific to This Standard:3.2.1 adjacent thermoelement configuration,nthermoelement configuration within a multi-pair thermo-couple or cable where two or more positive thermoelements areimmediately adjacent to one another around the circular patternand two
18、or more negative thermoelements are also immediatelyadjacent to one another around the circular pattern as shown inFig. 1 (compare with alternating thermoelement configurationin Fig. 2 and 3.2.2).3.2.1.1 DiscussionBy default, a multi-pair thermocoupleor cable with a thermoelement in the center shall
19、 be consideredan adjacent configuration.3.2.2 alternating thermoelement configuration,nthermoelement configuration within a multi-pair thermo-couple or cable where positive thermoelements and negativethermoelements alternate around the circular pattern as shownin Fig. 2 (compare with adjacent thermo
20、element configurationin Fig. 1 and 3.2.1).3.2.2.1 DiscussionIn an alternating thermoelement pat-tern, there are never two or more positive thermoelements nortwo or more negative thermoelements immediately adjacent toone another.3.2.3 common ungrounded junction, nmeasuring junctionwithin the same mul
21、ti-pair thermocouple that is electricallyisolated from the sheath but electrically connected to anotherungrounded junction.3.2.4 isolated ungrounded junction, nmeasuring junctionwithin the same multi-pair thermocouple that is electricallyisolated from the sheath and electrically isolated from all ot
22、herjunctions.3.2.5 lot, nquantity of finished MIMS thermocouples, orlength of MIMS thermocouple cable manufactured from tubingor other sheath material from the same heat, wire from thesame spool and heat, and insulation from the same batch, thenassembled and processed at the same time under controll
23、edproduction conditions to the required final configuration.3.2.6 raw material, nsheath, insulation, and wire materi-als used in the fabrication of the sheathed thermocouples orthermocouple cable.4. Significance and Use4.1 Types S, R, and B noble metal thermocouples aregenerally specified for use wh
24、en temperatures exceed the upperrecommended operating temperatures of base metal thermo-couples (see Specification E608/E608M).4.2 To optimize elevated temperature stability, Types S, R,and B thermocouples should be supplied with noble metalsheaths (see 6.3.1). Purchasers and users are cautioned tha
25、t ifTypes S, R, and B thermocouples are supplied with base metalsheaths, such as 300 series stainless steels or other heat-resistant nickel-chrome alloys, and are used at temperaturesexceeding 600C 1100F, they will be more susceptible todrift due to contamination and the development of inhomoge-neit
26、y. The higher the temperature, the faster the contamination,inhomogeneity, and resultant drift will develop. In some cases,the elevated temperature performance of a noble metal ther-mocouple with a base metal sheath will be inferior to that of abase metal thermocouple with a base metal sheath.5. Ord
27、ering Information and Basis for Purchase5.1 The purchasing documents shall specify the followingfor both thermocouples and cable:5.1.1 The nominal outside diameter of the sheath (see Table1).5.1.2 The type and quantity of noble metal thermoelements(see 6.1). Note that non-letter designated noble met
28、al thermo-elements (that is, other than Types S, R, and B) may be usedwith purchaser and producer agreement.5.1.3 The ceramic insulation (see 6.2). Note that otherinsulation composition and impurity levels may be used withpurchaser and producer agreement.5.1.4 The sheath material (see 6.3), and whet
29、her it shall beseamless or welded and drawn. Note that other sheath materialmay be used with purchaser and producer agreement.5.1.5 The intended operating temperature range of thethermocouple or cable (see 8.1.5).5.1.6 The tolerance of initial values of emf versus tempera-ture if other than standard
30、 for Types S, R, and B thermocouples(see Table 2), or the emf versus temperature relationship andinitial tolerance values if other than Types S, R, or B thermo-couples (see 8.1.5 and Guide E1751/E1751M).5.1.7 Optional supplementary testing and test sample ratesor optional material requirements (see
31、Supplementary Require-ments).3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.FIG. 1 Examples of Adjacent ConfigurationsFIG. 2 Examples of Alternating ConfigurationsE2181/E2181M 1125.1.8 Packaging method and straightness criteria, if required
32、(see 11.3).5.1.9 The quality assurance and verification program re-quirements (see Appendix X1).5.1.10 Any deviations from this specification or its Refer-enced Documents.5.2 In addition, the purchasing documents shall specify thefollowing when purchasing thermocouples:5.2.1 The style of measuring j
33、unction, Style G (grounded)or Style U (ungrounded). See Figs. 8 and 9. If more than onepair of thermoelements is specified, Style U is further subdi-vided into Style CU (common ungrounded) and Style IU(isolated ungrounded).45.2.2 The quantity, sheath length, and sheath length toler-ance of each ther
34、mocouple. See Figs. 3-6 for examples.5.2.3 The type and configuration of connection head, con-nector, transition piece, or termination, and moisture sealrequired on the end opposite the measuring junction. See Figs.3-6 for examples. The minimum and maximum intendedoperating temperatures of the conne
35、ction head, transition,termination, or moisture seal should be specified (see 6.5). Forthermocouples with insulated wire attached (see Fig. 6) andStyle U junctions, the minimum acceptable insulation resis-tance (see 8.1.3.2) shall be stated.5.3 In addition, the purchasing documents shall specify the
36、following when purchasing thermocouple cable:5.3.1 The thermoelement configuration (see 3.2.1 and3.2.2). Consult individual manufacturers for the availablenumber of thermoelements within a cable size.5.3.2 The total length and tolerance of finished thermo-couple cable, and the length and length tole
37、rance of each pieceof finished thermocouple cable.5.3.3 The kind of end seal applied to the open ends, prior toshipment (see 11.1).6. Material and Manufacturing Requirements6.1 Thermoelements:6.1.1 The thermoelements shall only be noble metal, andshall be of thermoelectric Type S, R, or B unless oth
38、erwiseagreed upon between the purchaser and producer.6.1.2 The thermoelements shall be solid wire, round in crosssection. The thermocouple or cable producer shall ensure thatall wire used for fabrication shall be free of visible surfaceoxides, scale, and contaminants, such as drawing compounds,carbo
39、n, dirt, and dust. The absence of scale and contaminantscan be verified by wiping the wire with a solvent-saturatedlint-free cloth. Acetone, isopropyl alcohol, methanol, andethanol are all acceptable solvents. A light discoloration of thecloth is acceptable unless particles of grit or metal flakes a
40、revisually detectable without the use of magnification. If acetoneor any other solvent that leaves a harmful residual film uponevaporation is used for initial cleaning, a final cleaning with anacceptable cleaning solvent, such as isopropyl alcohol, metha-nol, or ethanol is required.6.1.3 The initial
41、 emf versus temperature relationship forTypes S, R, and B thermoelements shall satisfy the standardtolerance specified in Table 2 unless otherwise stated in theordering information.6.2 Insulation:6.2.1 The insulation shall only be magnesia (MgO) oralumina (Al2O3) conforming to Specification E1652. U
42、nlessotherwise agreed upon between the purchaser and producer,only Type 1 magnesia or Type 1 alumina shall be used. See8.2.13 and Supplementary Requirement S11.6.2.2 The minimum density of the compacted insulationshall be 70 % of the maximum theoretical density which is3580 kg/m30.129 lb/in.3 for Mg
43、O, and 3970 kg/m30.144lb/in.3 forAl2O3.5See 8.2.12 and Supplementary RequirementS10.4Style G, Style U, Style CU and Style IU measuring junctions were previouslytermed Class 1, Class 2, Class 2A and Class 2B measuring junctions respectively.5Handbook of Chemistry and Physics, Chemical Rubber Publishi
44、ng Co., No. 76(1995) edition.TABLE 1 Preferred Outside Diameters, A, for Thermocouples andCable in SI (Metric) and Inch-Pound UnitsDiametermillimetres inches0.50 0.020. . . 0.0321.00 0.0401.50 0.0622.00 . . . . . 0.0933.00 0.1254.50 0.1886.00 0.2508.00 0.375E2181/E2181M 1136.3 Sheath:6.3.1 The sheat
45、h material may be seamless or welded anddrawn tubing of platinum, platinum-6 % rhodium, platinum-10 % rhodium, platinum-20 % rhodium, or platinum-30 %rhodium. The producers customary sheath material specifica-tion may be used.6.3.2 Alternately, heat-resistant nickel-chrome alloy tubingper Specificat
46、ions B163, B167,orB516; or 310 or 321stainless steel tubing per Specifications A213/A213M, A249/A249M, A269,orA632 may be supplied as sheath materialsprovided there is an agreement between the purchaser andproducer (see 4.2) and the annealing requirements imposed by6.3.4 are satisfied. The producers
47、 customary sheath materialspecification may be used.6.3.3 The thermocouple or cable producer shall ensure thateach piece of sheath material shall be free of visible surfaceoxides, scale, and contaminants, such as drawing compounds,carbon, dirt, and dust. The absence of scale and contaminantscan be v
48、erified by passing a solvent-saturated swatch oflint-free yarn or cloth against the inner surface of the sheathmaterial.Acetone, isopropyl alcohol, methanol, and ethanol areall acceptable solvents. A light discoloration of the swatch orplug is acceptable unless particles of grit or metal flakes arev
49、isually detectable without the use of magnification. If acetoneor any other solvent that leaves a harmful residual film uponevaporation is used for initial cleaning, a final cleaning with anacceptable cleaning solvent, such as isopropyl alcohol, metha-nol, or ethanol is required.6.3.4 The sheath shall be free of visible surface contami-nants and oxidation and shall be in the fully annealed state.Tests for proving conformance are in Supplementary Require-ment S7 or S12.6.3.5 The sheath of the finished thermocouple or cable shallexclude gases and liquids. There s
