1、Designation: E 2181/E 2181M 06e1Standard Specification forCompacted Mineral-Insulated, Metal-Sheathed, Noble MetalThermocouples and Thermocouple Cable1This standard is issued under the fixed designation E 2181/E 2181M; the number immediately following the designation indicates theyear of original ad
2、option or, in the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTEEditorial changes were made in 1.3 and 5.2.1 in November 2006.1. Scope1.1 T
3、his specification establishes dimensional and materialrequirements for compacted, mineral-insulated, metal-sheathed, 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.
4、This specification also establishes di-mensional and material requirements for compacted, mineral-insulated, metal-sheathed cable with at least one noble metalthermoelement pair.1.2 This specification describes both the required processingand testing requirements and also the optional supplementaryt
5、esting and quality assurance requirements.1.3 Provisions are made for selecting the type of noblemetal 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
6、 thermocouple measuring junctionstyle and for a transition or termination.1.4 The values stated in 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 T
7、his 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 requirements prior to use.2. Referenced Docum
8、ents2.1 The following documents of the latest issue form a partof this specification to the extent specified herein. In the eventof a conflict between this specification and other specificationsreferenced herein, this specification shall take precedence.2.2 ASTM Standards:2A 213/A 213M Specification
9、 for Seamless Ferritic andAus-tenitic Alloy-Steel Boiler, Superheater, and Heat-Exchanger TubesA 249/A 249M Specification for Welded Austenitic SteelBoiler, Superheater, Heat-Exchanger, and CondenserTubesA 269 Specification for Seamless and Welded AusteniticStainless Steel Tubing for General Service
10、A 632 Specification for Seamless and Welded AusteniticStainless Steel Tubing (Small-Diameter) for General Ser-viceB 163 Specification for Seamless Nickel and Nickel AlloyCondenser and Heat-Exchanger TubesB 167 Specification for Nickel-Chromium-Iron Alloys(UNS N06600, N06601, N06603, N06690, N06693,N
11、06025, and N06045)* and Nickel-Chromium-Cobalt-Molybdenum Alloy (UNS N06617) Seamless Pipe andTubeB 516 Specification for Welded Nickel-Chromium-Iron Al-loy (UNS N06600, UNS N06603, UNS N06025, and UNSN06045) TubesE 165 Test Method for Liquid Penetrant ExaminationE 220 Test Method for Calibration of
12、 Thermocouples ByComparison TechniquesE 230 Specification and Temperature-Electromotive Force(EMF) Tables for Standardized ThermocouplesE 344 Terminology Relating to Thermometry and Hydrom-etryE 608/E 608M Specification for Mineral-Insulated, Metal-Sheathed Base Metal ThermocouplesE 839 Test Methods
13、 for Sheathed Thermocouples andSheathed Thermocouple MaterialE 1652 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 Subcomm
14、ittee E20.04on Thermocouples.Current edition approved May 1, 2006. Published May 2006. Originallyapproved in 2001. Last previous edition approved in 2001 as E 2181/E 2181M 01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For
15、 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, Base M
16、etal Thermocouples, and Noble MetalThermocouplesE 1751 Guide for Temperature Electromotive Force (EMF)Tables for Non-Letter Designated Thermocouple Combi-nations2.3 ANSI Standard:3B46.1 Surface Texture2.4 AWS Standard:4A5.14 Specification for Nickel and Nickel-Alloy BareWelding Rods and Electrodes3.
17、 Terminology3.1 DefinitionsThe definitions given in TerminologyE 344 shall apply to this 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 ther
18、moelements areimmediately adjacent to one another around the circular patternand two 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).3.2.1.1 DiscussionBy default,
19、 a multi-pair thermocoupleor cable with a thermoelement in the center must 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 a
20、round the circular pattern as shownin Fig. 2 (compare with adjacent thermoelement configurationin Fig. 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 co
21、mmon ungrounded junction, nmeasuring junc-tions within the same multi-pair thermocouple that are electri-cally isolated from the sheath but electrically connected to eachother.3.2.4 isolated ungrounded junction, nmeasuring junctionswithin the same multi-pair thermocouple that are electricallyisolate
22、d from the sheath and electrically isolated from eachother.3.2.5 lot, nquantity of finished mineral-insulated, metal-sheathed thermocouples, or length of thermocouple cablemanufactured from tubing from the same heat, wire from thesame spool and heat, and insulation from the same batch, thenassembled
23、 and processed together under controlled productionconditions to the required final configuration.3.2.6 raw material, ntubing, insulation, and wires used infabrication of the sheathed thermocouples or thermocouplecable.4. Significance and Use4.1 Type S, R, and B noble metal thermocouples aregenerall
24、y specified for use when temperatures exceed the upperrecommended operating temperatures of base metal thermo-couples (see Specification E 608/E 608M).4.2 To optimize elevated temperature stability, Type S, R,and B thermocouples should be supplied with noble metalsheaths (see 6.3.1). Purchasers and
25、users are cautioned that ifType 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 600 C 1100 F, they will be more susceptible todrift due to contamination and the deve
26、lopment of inhomoge-neity. The higher the temperature, the faster the contamination,inhomogeneity, and resultant drift develop. In some cases, theelevated temperature performance of a noble metal thermo-couple with a base metal sheath will be inferior to that of a basemetal thermocouple with a base
27、metal sheath.5. Ordering 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 d
28、esignated noble metal thermo-elements (that is, other than Types S, R, and B) may be usedupon purchaser and producer agreement.5.1.3 The kind of ceramic insulation (see 6.2). Note thatother insulation composition and impurity levels may be usedwith purchaser and producer agreement.5.1.4 The kind of
29、sheath material (see 6.3), and whether itshall be seamless or welded and drawn. Note that other sheathmaterial may 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
30、tempera-ture if other than standard for Types S, R, and B thermo-couples, or the emf versus temperature relationship and initial3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.4Available from American Welding Society (AWS), 550 NW LeJeune Rd
31、.,Miami, FL 33126.FIG. 1 Examples of Adjacent ConfigurationsFIG. 2 Examples of Alternating ConfigurationsE 2181/E 2181M 06e12tolerance values if other than Type S, R, or B thermocouples(see 8.1.5 and Guide E 1751).5.1.7 Optional supplementary testing and test sample ratesor optional material require
32、ments (see Supplementary Require-ments).5.1.8 Packaging method and straightness criteria, if required(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 purchas
33、ing documents shall specify thefollowing if purchasing thermocouples:5.2.1 The style of measuring junction, 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
34、(isolated ungrounded).55.2.2 The quantity, sheath length, and sheath length toler-ance of each thermocouple. 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 junct
35、ion. See Figs.3-6 for examples. The minimum and maximum intendedoperating temperature of the connection head, transition, ter-mination, or moisture seal should be specified (see 6.5). Forthermocouples with insulated wire attached (see Fig. 6) andStyle U junctions, state the minimum acceptable insula
36、tionresistance (see 8.1.3.2).5.3 In addition, the purchasing documents shall specify thefollowing if 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 tota
37、l length and tolerance of finished thermo-couple cable, and the length and length tolerance 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 thermoelemen
38、ts shall only be noble metal, andshall be of thermoelectric types S, R, or B unless otherwiseagreed upon between purchaser and producer.6.1.2 The thermoelements shall be solid wire, round in crosssection. All wire used for fabrication shall meet the supple-mental cleanliness requirements of Specific
39、ation A 632, exceptthat acetone or any other solvents that might leave a harmfulresidue shall not be used for final cleaning.5Style G, Style U, Style CU and Style IU measuring junctions were previouslytermed Class 1, Class 2, Class 2A and Class 2B measuring junctions respectively.TABLE 1 Preferred O
40、utside 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 0.375FIG. 3 Sheathed Thermocouple CableFIG. 4 Sheathed Thermocouple with Exposed Thermoelements
41、FIG. 5 Sheathed Thermocouple Assembly with Connector orConnection Head (any Type Specified)FIG. 6 Sheathed Thermocouple Assembly with Transition PieceFIG. 7 Sheathed Thermocouple ConstructionE 2181/E 2181M 06e136.1.3 The initial emf versus temperature relationship forType S, R, and B thermoelements
42、shall satisfy the standardtolerance specified by Specification E 230 unless otherwisestated in the ordering information.6.2 Insulation:6.2.1 The insulation shall only be magnesia (MgO) oralumina (Al2O3) conforming to Specification E 1652. Unlessotherwise agreed upon between purchaser and producer, o
43、nlyType 1 magnesia or Type 1 alumina shall be used. See 8.2.13and 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 MgO, and 3970 kg/m30.144lb/in.3 forAl2O3.6See 8.2.12 and Supplemen
44、tary RequirementS10.6.3 Sheath:6.3.1 The sheath material may be seamless or welded anddrawn tubing of platinum, platinum-10 % rhodium, platinum-20 % rhodium, or platinum-30 % rhodium. The producerscustomary tubing specification may be used.6.3.2 Alternately, heat-resistant nickel-chrome alloy tubing
45、per Specifications B 163, B 167,orB 516; or 310 or 321stainless steel tubing per Specifications A 213/A 213M, A 249/A 249M, A 269,orA 632 may be supplied as sheath materialsprovided there is an agreement between purchaser and pro-ducer (see 4.2) and the annealing requirements imposed by6.3.4 are sat
46、isfied. The producers customary tubing specifica-tion may be used.6.3.3 Each piece of tubing shall meet the supplementalcleanliness requirements of Specification A 632, except thatacetone or any other solvents that might leave a harmfulresidue may not be used for final cleaning.6.3.4 The sheath shal
47、l 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 shall be no holes, cracks, orother
48、void defects that penetrate through the sheath wall. Testsfor proving conformance to this requirement are in Supplemen-tary Requirements S2, S3, S4, and S5.6.4 The end closure of thermocouples shall be seal weldedand shall be impervious to gases and liquids. There shall be nocracks, holes, or void d
49、efects that penetrate through the metal6Handbook of Chemistry and Physics, Chemical Rubber Publishing Co., No. 76(1995) edition.FIG. 8 Grounded Measuring Junction, Style GFIG. 9 Ungrounded Measuring Junction, Style UE 2181/E 2181M 06e14wall. Any mineral oxide removed during fabrication of themeasuring junction shall be replaced with dry oxide of thesame type that conforms to the purity requirements of Speci-fication E 1652. Style U measuring junctions shall be fabri-cated by welding the thermoelements together without fillermetal or flux. The use of plugs or
