1、Designation: E230/E230M 12 An 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
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 the1These tables are under the jurisdiction of ASTM Committee E20 on Tempera-ture Measurement and are
16、 the direct responsibility of Subcommittee E20.04 onThermocouples.Current edition approved Nov. 1, 2012. Published November 2012. Originallyapproved in 1963. Last previous edition approved in 2011 as E230 111. DOI:10.1520/E0230_E0230M-12.2These temperature-emf relationships have been revised as requ
17、ired 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 States1responsibility of the user of this standard to establish appro-priate safety and health pra
18、ctices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3E235 Specification for Thermocouples, Sheathed, Type Kand Type N, for Nuclear or for Other High-ReliabilityApplicationsE574 Specification for Duplex, Base Metal ThermocoupleWire
19、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 Specification for Thermocouple Materials, Platinum-Rhodium All
20、oys, 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 Tables for the Letter-DesignatedThermocouple Types Based on the ITS
21、-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 Scale of 1990 (ITS-90).3.2 The temperature-emf data in Tables 8 t
22、o 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 in Tables 7and 46 have been developed from curves fitted to wire
23、manufacturers 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 decimalplaces (1 V) at temperature intervals of one degree. The tablesare s
24、atisfactory 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 places (0.1 V) for each type except Type C. Equa-tions which permi
25、t 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 given in Table 46.4. Thermocouple Types and Letter Designations4
26、.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 Type ENickel-10 % chromium (+) versus copper-45 % nickel (constan
27、tan) ().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 elements.4.1.5 Type NNickel-14 % chromium, 1.5 % silicon (+)versus n
28、ickel-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-5 % Rhenium (+) versus Tungsten-26 % Rhenium ().4.2 Each lette
29、r 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 composition.4.3 The thermoelement identifying symbols in Tables 26
30、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 respect to plati-num (NIST Pt-67). The appropriate letter designation
31、 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,JNX) denotes an “extension grade” material whose thermo-electric
32、 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 with which they are intended to be used, whereas thecompensating
33、extension wires for noble metal 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 approximate3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcont
34、act 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 in NIS
35、TTechnical Note 1263, Guidelines for Implementing the NewRepresentations of the Volt and Ohm Effective January 1, 1990.E230/E230M 122those 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 versusT
36、emperature5.1 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 emf versus temperaturefor single-leg thermoelements referenced
37、 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 on initialvalues of emf versus temperature for single thermoel
38、ementsshould 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. This indicates that thetemperature-electromotive force relationshi
39、p 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 interchangeable withthose of the other, or that they have the same mi
40、llivolttolerances 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 and 3,respectively.5.2.1 Initial tolerances of extension grade
41、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. Color Coding6.1 Color codes for insulation on thermocouple gradem
42、aterials, 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, where letter designations for the extension thermoele-ments and p
43、airs 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 information.7. List of Tables7.1 Following is a list of the table
44、s included in this standard:7.1.1 General Tables:TableNumberTitle1 Tolerances on Initial Values of Emf versus Temperature forThermocouples2 Tolerances on Initial Values of Emf versus Temperature forExtension Wires3 Tolerances on Initial Values of Emf versus Temperature forCompensating Extension Wire
45、s4 United States Color Codes for Single and Duplex InsulatedThermocouple Wire5 United States Color Codes for Single and Duplex InsulatedExtension Wire6 Suggested Upper Temperature Limits for ProtectedThermocouples7 Polynomial Coefficients for Generating Thermocouple Emf as aFunction of Temperature7.
46、1.2 Emf versus Temperature Tables for Thermocouples:TableNumberThermocoupleTypeTemperatureRangeA8 B 0 to 1820C9 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
47、 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 Temperature 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 76
48、0C31 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 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
49、270 to 1000C45 T or E TN or EN 454 to 1832FAThese temperature ranges represent the published temperature versus emf datafor 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:TableNumberTitle46 Coefficients of Inverse Polynomials for Computationof Approximate Temperature as a Function ofThermocouple EmfE230/E230M 1238. Keywords8.1 emf computation; compens
