1、Designation: E230/E230M 17 An American National StandardStandard Specification forTemperature-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
2、adoption 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 gi
3、ve 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
4、may 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 compensati
5、ng 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 insul
6、ation 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-legthermoe
7、lements 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
8、RP 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 func
9、tion 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 thermo
10、couples, 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 compu
11、ting 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 rel
12、ationshipspresented in the tables of this standard and bear the letterdesignations contained herein. Topics such as orderinginformation, physical and mechanical properties,workmanship, testing, and marking are not addressed in thisspecification. The user is referred to specific standards such asSpec
13、ifications E235, 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 unit
14、s or inch-pound unitsare to be regarded separately as standard.1.12.1 The values stated in brackets are not conversions tothe values they succeed and therefore shall be used indepen-dently of the preceding values.1.12.2 The values given in parentheses are conversions ofthe values they succeed.1.12.3
15、 Combining values from the two systems may resultin non-conformance with the standard.1.13 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is the1This specification is under the jurisdiction of ASTM Committee E20 onTemperature Measurement and
16、are the direct responsibility of Subcommittee E20.11on Thermocouples - Calibration.Current edition approved Nov. 1, 2017. Published November 2017. Originallyapproved in 1963. Last previous edition approved in 2012 as E230/E230M 12.DOI: 10.1520/E0230_E0230M-17.2These temperature-emf relationships hav
17、e been revised as required by theinternational adoption in 1989 of a revised International Temperature Scale(ITS-90).Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internati
18、onally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1responsibility of the user of this standard to estab
19、lish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.14 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopm
20、ent of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:3E235 Specification for Thermocouples, Sheathed, Type Kand Type N, for Nuclear or for Other High-ReliabilityApplicat
21、ionsE574 Specification for Duplex, Base Metal ThermocoupleWire With Glass Fiber or Silica Fiber InsulationE585/E585M Specification for Compacted Mineral-Insulated, Metal-Sheathed, Base Metal ThermocoupleCableE608/E608M Specification for Mineral-Insulated, Metal-Sheathed Base Metal ThermocouplesE1159
22、 Specification for Thermocouple Materials, Platinum-Rhodium Alloys, and PlatinumE2181/E2181M Specification for Compacted Mineral-Insulated, Metal-Sheathed, Noble Metal Thermocouplesand Thermocouple Cable2.2 NIST Monograph:NIST Monograph 175 Temperature-Electromotive ForceReference Functions and Tabl
23、es for the Letter-DesignatedThermocouple Types Based on the ITS-9042.3 IEC Standard:IEC 5843 Thermocouples Part 3: Extension and Compen-sating Cables Tolerances and Identification System, 19893. Source of Data3.1 The data in these tables are based upon the SI volt5andthe International Temperature Sc
24、ale 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 Type C, have been extractedfrom NIST Monograph 175. Temperature-emf data inTables 24 and 25 and the coefficients for Type C i
25、n 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 information is required, the reader should consultNIST Monograph 175.3.3 These tables give emf values to three decimalplace
26、s (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 greaterprecision is required, the reader should refer to NIST Mono-graph 175 which includes tables giving emf values to fourdecimal pla
27、ces (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, coefficients of inverse polynomials that may beused to calculate approximate temperature (C) as a function ofthermocouple emf are g
28、iven 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 andidentify the following thermocouple calibrations:4.1.1 Type BPlatinum-30 % rhodium (+) versus platinum-6 % rhodium ().4.1.2 Ty
29、pe 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 (+) versus nickel-5 % (aluminum, silicon) ().NOTE 2Silicon, or aluminum and silicon, may be present in combi-nation with other eleme
30、nts.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 SPlatinum-10 % rhodium (+) versus platinum().4.1.8 Type TCopper (+) versus copper-45 % nickel (con-stantan) ().4.1.9 Type CTungsten
31、-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 thermocouple conforming thereto within statedtolerances on initial values of emf versus temperature, regard-less of its comp
32、osition.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 thermocoupletype.4.4 Tables 26 to 45 identify specific temperature-emf rela-tionships of individual thermoelements with respec
33、t 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 conformingto the corresponding table within the stated tolerances.4.5 An overall suffix letter “X” (for example KX, TX, EPX,J
34、NX) denotes an “extension grade” material whose thermo-electric properties will match those of the correspondingthermocouple type within the stated extension grade tolerancesover a limited temperature range. Most base metal extensionwires have the same nominal composition as the thermocouplewires wi
35、th which they are intended to be used, whereas the3For referenced ASTM standards, visit the ASTM website, www.astm.org, 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
36、from National Institute of Standards and Technology (NIST), 100Bureau Dr., Stop 1070, Gaithersburg, MD 20899.5Discussed in NISTTechnical Note 1263, Guidelines for Implementing the NewRepresentations of the Volt and Ohm Effective January 1, 1990.E230/E230M 172compensating extension wires for noble me
37、tal or refractorymetal thermocouple types (S, R, B, or C) are usually of adifferent, more economical composition whose relative ther-moelectric properties as a pair nonetheless closely approximatethose of the noble metal or refractory metal thermocoupleswith which they are to be used over a limited
38、temperaturerange.5. Tolerances on Initial Values of Emf versusTemperature5.1 In the United States, thermocouples and matched ther-mocouple wire pairs are normally supplied conforming to thetolerances on initial values of emf versus temperature providedin Table 1.5.1.1 Tolerances on initial values of
39、 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 equivalent to onehalf the millivolt tolerance of the Type K thermocouple.5.1.2 For all other thermocouple types, tolerances
40、 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, the thermoelements areidentified by two thermoelement symbols indicating theirapplicability to two thermocouple types. Thi
41、s indicates that thetemperature-electromotive force relationship of the table istypical of the referenced thermoelements over the temperaturerange given in Table 1 for the corresponding thermocoupletype. It should not be assumed, however, that thermoelementsused with one thermocouple type are interc
42、hangeable 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 compensating exten-sion wires are supplied to conform to the tolerances on initialvalues of emf versus temperature shown in Tables 2
43、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 thermocouplegrade materials.Applicable temperature ranges, consistent withtypical usage, are given in Tables 2 and 3.6. Co
44、lor Coding6.1 Color codes for insulation on thermocouple gradematerials, along with corresponding thermocouple and thermo-element letter designations, are given in Table 4.6.2 Extension wires for thermocouples are distinguished byhaving an identifying color in the outer jacket as shown inTable 5, wh
45、ere 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 States.NOTE 3Other insulation color coding conventions may be found inuse elsewhere in the world. Refer to Appendix X1 for in
46、formation.7. List of Tables7.1 Following is a list of the tables included in this standard:7.1.1 General Tables:TableNumberTitle1 Tolerances on Initial Values of Emf versus Temperature for Thermo-couples2 Tolerances on Initial Values of Emf versus Temperature for Exten-sion Wires3 Tolerances on Init
47、ial Values of Emf versus Temperature for Com-pensating Extension Wires4 United States Color Codes for Single and Duplex Insulated Thermo-couple Wire5 United States Color Codes for Single and Duplex Insulated Exten-sion Wire6 Suggested Upper Temperature Limits for Protected Thermocouples7 Polynomial
48、Coefficients for Generating Thermocouple Emf as aFunction of Temperature7.1.2 Emf versus Temperature Tables for Thermocouples:Table Number Thermocouple Type Temperature RangeA8 B 0 C to 1820 C9 B 32 F to 3308 F10 E -270 C to 1000 C11 E -454 F to 1832 F12 J -210 C to 1200 C13 J -346 F to 2192 F14 K -
49、270 C to 1372 C15 K -454 F to 2500 F16 N -270 C to 1300 C17 N -454 F to 2372 F18 R -50 C to 1768 C19 R -58 F to 3214 F20 S -50 C to 1768 C21 S -58 F to 3214 F22 T -270 C to 400 C23 T -454 F to 752 F24 C 0 C to 2315 C25 C 32 F to 4200 F7.1.3 Emf versus Temperature Tables for Thermoelements:Table Num-berThermo-couple TypeThermoelementTypeTemperature RangeA26 B BP 0 C to 1768 C27 B BP 32 F to 3214 F28 B BN 0 C to 1768 C29 B BN 32 F to 3214 F30 J JP -210 C to 760 C31 J JP -346 F to 1400 F32 J JN -210 C to 760
