1、Designation: E230/E230M 11An American National StandardStandard Specification andTemperature-Electromotive Force (emf) Tables forStandardized Thermocouples1This standard is issued under the fixed designation E230/E230M; the number immediately following the designation indicates the yearof original a
2、doption 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 contains reference tables (Tables 8 to25) that giv
3、e temperature-electromotive force (emf) relation-ships for Types B, E, J, K, N, R, S, T, and C thermocouples.2These are the thermocouple types most commonly used inindustry. The tables contain all of the temperature-emf datacurrently available for the thermocouple types covered by thisstandard and m
4、ay include data outside of the recommendedupper temperature limit of an included thermocouple type.1.2 In addition, the specification includes standard andspecial tolerances on initial values of emf versus temperaturefor thermocouples (Table 1), thermocouple extension wires(Table 2), and compensatin
5、g extension wires for thermo-couples (Table 3). Users should note that the stated tolerancesapply only to the temperature ranges specified for the thermo-couple types as given in Tables 1, 2, and 3, and do not apply tothe temperature ranges covered in Tables 8 to 25.1.3 Tables 4 and 5 provide insula
6、tion color coding forthermocouple and thermocouple extension wires as customar-ily used in the United States.1.4 Recommendations regarding upper temperature limitsfor the thermocouple types referred to in 1.1 are provided inTable 6.1.5 Tables 26 to 45 give temperature-emf data for single-legthermoel
7、ements referenced to platinum (NIST Pt-67). Thetables include values for Types BP, BN, JP, JN, KP (same asEP), KN, NP, NN, TP, and TN (same as EN).1.6 Tables for Types RP, RN, SP, and SN thermoelementsare not included since, nominally, Tables 18 to 21 represent thethermoelectric properties of Type R
8、P and SP thermoelementsreferenced to pure platinum. Tables for the individual thermo-elements of Type C are not included because materials for TypeC thermocouples are normally supplied as matched pairs only.1.7 Polynomial coefficients which may be used for compu-tation of thermocouple emf as a funct
9、ion of temperature aregiven in Table 7. Coefficients for the emf of each thermocouplepair as well as for the emf of most individual thermoelementsversus platinum are included. Coefficients for type RP and SPthermoelements are not included since they are nominally thesame as for types R and S thermoc
10、ouples, and coefficients fortype RN or SN relative to the nominally similar Pt-67 would beinsignificant. Coefficients for the individual thermoelements ofType C thermocouples have not been established.1.8 Coefficients for sets of inverse polynomials are given inTable 46. These may be used for comput
11、ing a close approxi-mation of temperature (C) as a function of thermocouple emf.Inverse functions are provided only for thermocouple pairs andare valid only over the emf ranges specified.1.9 This specification is intended to define the thermoelec-tric properties of materials that conform to the rela
12、tionshipspresented in the tables of this standard and bear the letterdesignations contained herein. Topics such as ordering infor-mation, physical and mechanical properties, workmanship,testing, and marking are not addressed in this specification.Theuser is referred to specific standards such as Spe
13、cificationsE235, E574, E585/E585M, E608/E608M, E1159,orE2181/E2181M for guidance in these areas.1.10 The temperature-emf data in this specification areintended for industrial and laboratory use.1.11 Thermocouple color codes per IEC 5843 are given inAppendix X1.1.12 The values stated in either SI uni
14、ts or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, each1These tables are under the jurisdiction of ASTM Committee E20 on Tempera-ture Measurement and are the direct responsibility of Subcommittee E20.04 onThermoco
15、uples.Current edition approved May 15, 2011. Published August 2011. Originallyapproved in 1963. Last previous edition approved in 2003 as E230 03. DOI:10.1520/E0230_E0230M-11.2These temperature-emf relationships have been revised as required by theinternational adoption in 1989 of a revised Internat
16、ional Temperature Scale(ITS-90).1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.system shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.13 This standard d
17、oes 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.2. Referenced Documents2.1 ASTM St
18、andards:3E235 Specification for Thermocouples, Sheathed, Type Kand Type N, for Nuclear or for Other High-ReliabilityApplicationsE574 Specification for Duplex, Base Metal ThermocoupleWire With Glass Fiber or Silica Fiber InsulationE585/E585M Specification for Compacted Mineral-Insulated, Metal-Sheath
19、ed, Base Metal ThermocoupleCableE608/E608M Specification for Mineral-Insulated, Metal-Sheathed Base Metal ThermocouplesE1159 Specification for Thermocouple Materials, Platinum-Rhodium Alloys, and PlatinumE2181/E2181M Specification for Compacted Mineral-Insulated, Metal-Sheathed, Noble Metal Thermoco
20、uplesand Thermocouple Cable2.2 NIST Monograph:NIST Monograph 175 Temperature-Electromotive ForceReference Functions and Tables for the Letter-DesignatedThermocouple Types Based on the ITS-9042.3 IEC Standard:IEC 5843 Thermocouples Part 3: Extension and Com-pensating Cables Tolerances and Identificat
21、ion System,19893. Source of Data3.1 The data in these tables are based upon the SI volt5andthe International Temperature Scale of 1990 (ITS-90).3.2 The temperature-emf data in Tables 8 to 23 and 26 to 45,together with the corresponding equations in Tables 7 and 46for all thermocouple types except Ty
22、pe C, have been extractedfrom NIST Monograph 175. Temperature-emf data inTables 24 and 25 and the coefficients for Type C in Tables 7and 46 have been developed from curves fitted to wiremanufacturers data.NOTE 1It is beyond the scope of this standard to discuss the origin ofthese tables. If further
23、information is required, the reader should consultNIST Monograph 175.3.3 These tables give emf values to three decimalplaces (1 V) at temperature intervals of one degree. The tablesare satisfactory for most industrial uses but may not beadequate for computer and similar applications. If greaterpreci
24、sion is required, the reader should refer to NIST Mono-graph 175 which includes tables giving emf values to fourdecimal places (0.1 V) for each type except Type C. Equa-tions which permit easy and unique generation of thetemperature-emf relationships can be found in Table 7. Forconvenience, coeffici
25、ents of inverse polynomials that may beused to calculate approximate temperature (C) as a function ofthermocouple emf are given in Table 46.4. Thermocouple Types and Letter Designations4.1 The letter symbols identifying each reference table arethose which are in common use throughout industry andide
26、ntify the following thermocouple calibrations:4.1.1 Type BPlatinum-30 % rhodium (+) versus platinum-6 % rhodium ().4.1.2 Type ENickel-10 % chromium (+) versus copper-45 % nickel (constantan) ().4.1.3 Type JIron (+) versus copper-45 % nickel (constan-tan) ().4.1.4 Type KNickel-10 % chromium (+) versu
27、s nickel-5 % (aluminum, silicon) ().NOTE 2Silicon, or aluminum and silicon, may be present in combi-nation with other elements.4.1.5 Type NNickel-14 % chromium, 1.5 % silicon (+)versus nickel-4.5 % silicon-0.1 % magnesium ().4.1.6 Type RPlatinum-13 % rhodium (+) versus platinum().4.1.7 Type SPlatinu
28、m-10 % rhodium (+) versus platinum().4.1.8 Type TCopper (+) versus copper-45 % nickel (con-stantan) ().4.1.9 Type CTungsten-5 % Rhenium (+) versus Tungsten-26 % Rhenium ().4.2 Each letter designation in 4.1 identifies a specifictemperature-emf relationship (Tables 8 to 25) and may beapplied to any t
29、hermocouple conforming thereto within statedtolerances on initial values of emf versus temperature, regard-less of its composition.4.3 The thermoelement identifying symbols in Tables 26 to45 use the suffix letters P and N to denote, respectively, thepositive and negative thermoelement of a given the
30、rmocoupletype.4.4 Tables 26 to 45 identify specific temperature-emf rela-tionships of individual thermoelements with respect to plati-num (NIST Pt-67). The appropriate letter designation may beapplied to any thermoelement which, when combined with itsmating thermoelement, will form a thermocouple co
31、nformingto the corresponding table within the stated tolerances.4.5 An overall suffix letter “X” (for example KX, TX, EPX,JNX) denotes an “extension grade” material whose thermo-electric properties will match those of the correspondingthermocouple type within the stated extension grade tolerancesove
32、r a limited temperature range. Most base metal extensionwires have the same nominal composition as the thermocouplewires with which they are intended to be used, whereas thecompensating extension wires for noble metal or refractory3For referenced ASTM standards, visit the ASTM website, www.astm.org,
33、 orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available from National Institute of Standards and Technology (NIST), 100Bureau Dr., Stop 1070, Gaithersburg, MD 20899.5Discussed
34、 in NISTTechnical Note 1263, Guidelines for Implementing the NewRepresentations of the Volt and Ohm Effective January 1, 1990.E230/E230M 112metal thermocouple types (S, R, B, or C) are usually of adifferent, more economical composition whose relative ther-moelectric properties as a pair nonetheless
35、closely approximatethose of the noble metal or refractory metal thermocoupleswith which they are to be used over a limited temperaturerange.5. Tolerances on Initial Values of Emf versusTemperature5.1 In the United States, thermocouples and matched ther-mocouple wire pairs are normally supplied confo
36、rming to thetolerances on initial values of emf versus temperature providedin Table 1.5.1.1 Tolerances on initial values of emf versus temperaturefor single-leg thermoelements referenced to platinum havebeen established only for Types KP and KN. These aresupplied, by common practice, to a tolerance
37、equivalent to onehalf the millivolt tolerance of the Type K thermocouple.5.1.2 For all other thermocouple types, tolerances on initialvalues of emf versus temperature for single thermoelementsshould be established by agreement between the purchaser andthe supplier.5.1.3 In Tables 34, 35, 44, and 45,
38、 the thermoelements areidentified by two thermoelement symbols indicating theirapplicability to two thermocouple types. This indicates that thetemperature-electromotive force relationship of the table istypical of the referenced thermoelements over the temperaturerange given in Table 1 for the corre
39、sponding thermocoupletype. It should not be assumed, however, that thermoelementsused with one thermocouple type are interchangeable withthose of the other, or that they have the same millivolttolerances for the initial values of emf versus temperature.5.2 Thermocouple extension wires and compensati
40、ng exten-sion wires are supplied to conform to the tolerances on initialvalues of emf versus temperature shown in Tables 2 and 3,respectively.5.2.1 Initial tolerances of extension grade materials andcompensating extension materials apply over a more limitedrange of temperature than the corresponding
41、 thermocouplegrade materials.Applicable temperature ranges, consistent withtypical usage, are given in Tables 2 and 3.6. Color Coding6.1 Color codes for insulation on thermocouple grade ma-terials, along with corresponding thermocouple and thermoele-ment letter designations, are given in Table 4.6.2
42、 Extension wires for thermocouples are distinguished byhaving an identifying color in the outer jacket as shown inTable 5, where letter designations for the extension thermoele-ments and pairs are also presented.6.3 Information presented in Tables 4 and 5 is based oncustomary practice in the United
43、States.NOTE 3Other insulation color coding conventions may be found inuse elsewhere in the world. Refer to Appendix X1 for information.7. List of Tables7.1 Following is a list of the tables included in this standard:7.1.1 General Tables:TableNumber Title1 Tolerances on Initial Values of Emf versus T
44、emperature forThermocouples2 Tolerances on Initial Values of Emf versus Temperature for Ex-tension Wires3 Tolerances on Initial Values of Emf versus Temperature forCompensating Extension Wires4 United States Color Codes for Single and Duplex InsulatedThermocouple Wire5 United States Color Codes for
45、Single and Duplex InsulatedExtension Wire6 Suggested Upper Temperature Limits for Protected Thermo-couples7 Polynomial Coefficients for Generating Thermocouple Emf as aFunction of Temperature7.1.2 Emf versus Temperature Tables for Thermocouples:TableNumberThermocoupleTypeTemperatureRangeA8 B 0 to 18
46、20C9 B 32 to 3308F10 E 270 to 1000C11 E 454 to 1832F12 J 210 to 1200C13 J 346 to 2192F14 K 270 to 1372C15 K 454 to 2500F16 N 270 to 1300C17 N 454 to 2372F18 R 50 to 1768C19 R 58 to 3214F20 S 50 to 1768C21 S 58 to 3214F22 T 270 to 400C23 T 454 to 752F24 C 0 to 2315C25 C 32 to 4200F7.1.3 Emf versus Te
47、mperature Tables for Thermoelements:Table Number Thermocouple TypeThermoele-ment TypeTemperatureRangeA26 B BP 0 to 1768C27 B BP 32 to 3214F28 B BN 0 to 1768C29 B BN 32 to 3214F30 J JP 210 to 760C31 J JP 346 to 1400F32 J JN 210 to 760C33 J JN 346 to 1400F34 K or E KP or EP 270 to 1372C35 K or E KP or
48、 EP 454 to 2500F36 K KN 270 to 1372C37 K KN 454 to 2500F38 N NP 200 to 1300C39 N NP 328 to 2372F40 N NN 200 to 1300C41 N NN 328 to 2372F42 T TP 270 to 400C43 T TP 454 to 752F44 T or E TN or EN 270 to 1000C45 T or E TN or EN 454 to 1832FAThese temperature ranges represent the published temperature ve
49、rsus emfdata for the thermocouple and thermoelement types listed. Refer to Table 6 for therecommended upper temperature limits for a specific thermocouple wire size andtype.7.1.4 Supplementary Table:TableNumberTitleE230/E230M 11346 Coefficients of Inverse Polynomials for Computationof Approximate Temperature as a Function of Ther-mocouple Emf8. Keywords8.1 emf computation; compensating extension wire; inversepolynomial; polynomial coefficient; reference tables; thermo-couple; thermoco
