1、Designation:E23506 Designation: E235/E235M 12Standard Specification forThermocouples, Sheathed, Type K and Type N Mineral-Insulated, Metal-Sheathed Thermocouples for Nuclear or forOther High-Reliability Applications1This standard is issued under the fixed designation E235/E235M; the number immediate
2、ly following the designation indicates the yearof original 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 spec
3、ification covers the requirements for simplex, compacted mineral-insulated, metal-sheathed (MIMS), Type K andN thermocouples for nuclear or other high reliability service. Depending on size, these thermocouples are normally suitable foroperating temperatures to 1652 F (900 C); 1652F 900C; special co
4、nditions of environment and life expectancy may permittheir use at temperatures in excess of 2012 F (1100 C). 2012F 1100C. This specification was prepared specifically to detailrequirements for using this type of sheathedMIMS thermocouple for use in nuclear environments. This specificationenvironmen
5、ts,but they can also be used for sheathed thermocouples which are required for laboratory or general commercial applications wherethe environmental conditions exceed normal service requirements. The intended use of a sheathedMIMS thermocouple in a specificnuclear application will require evaluation
6、by the purchaser of the compatibility of the thermocouple, including the effect of thetemperature, atmosphere, and integrated neutron flux on the materials and accuracy of the thermoelements in the proposedapplication by the purchaser.1.2 This specification does not attempt to include all possible s
7、pecifications, standards, etc., for materials that may be used assheathing, insulation, and thermocouple wires for sheathed-type construction. The requirements of this specification include onlythe austenitic stainless steels and other alloys as allowed withby Specification E585/E585M for sheathing,
8、 magnesium oxide oraluminum oxide as insulation, and Type K and N thermocouple wires for thermoelements (see Note 1).1.21.3 General DesignNominal sizes of the finished thermocouples shall be 0.0400 in. (1.016 mm), 0.0625 in. (1.588 mm), 0.125in. (3.175 mm), 0.1875 in. (4.763 mm), or 0.250 in. (6.350
9、 mm). Sheath dimensions and tolerances for each nominal size shallbe in accordance with Nominal sizes of the finished thermocouples shall be 0.0400 in., 0.0625 in., 0.125 in., 0.1875 in., or 0.250in. 1.000 mm, 1.500 mm, 3.000 mm, 4.500 mm, or 6.000 mm. Sheath dimensions and tolerances for each nomin
10、al size shall bein accordance with Table 1 and Figs. 1 and 2. The measuring junction styles for thermocouples covered by this specification areas follows:1.2.11.3.1 Style G2(grounded)Measuring junction electrically connected to conductive sheaths, and1.2.2The measuring junction is electrically conne
11、cted to its conductive sheath, and1.3.2 Style U2(ungrounded)Measuring junctions are electrically isolated from conductive sheaths and from reference ground.1.3The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for informationonly.1.4The meas
12、uring junction is electrically isolated from its conductive sheath and from reference ground.1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in eachsystem are not exact equivalents or conversions; therefore, each system shall
13、be used independently of the other. Combining valuesfrom the two systems may result in non-conformance with the standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish approp
14、riate safety and health practices and determine the applicability of regulatorylimitations prior to use.1This specification is under the jurisdiction of ASTM Committee E20 on Temperature Measurement and is the direct responsibility of Subcommittee E20.04 onThermocouples.Current edition approved Nov.
15、May 1, 2006.2012. Published November 2006.August 2012. Originally approved in 1964. Last previous edition approved in 20032006 asE235 036. DOI: 10.1520/E0235-06.10.1520/E0235-12.2Style G and Style U measuring junctions were previously termed Class 1 and Class 2 measuring junctions respectively.1This
16、 document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior edition
17、s as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.2. Referenced Documents2.1 ASTM Standards:3A262 Prac
18、tices for Detecting Susceptibility to Intergranular Attack in Austenitic Stainless SteelsE3 Guide for Preparation of Metallographic SpecimensE45 Test Methods for Determining the Inclusion Content of Steel E94Guide for Radiographic ExaminationE112 Test Methods for Determining Average Grain SizeE165 P
19、ractice for Liquid Penetrant Examination for General IndustryE220 Test Method for Calibration of Thermocouples By Comparison TechniquesE230 Specification and Temperature-Electromotive Force (EMF) Tables for Standardized ThermocouplesE344 Terminology Relating to Thermometry and HydrometryE585/E585M S
20、pecification for Compacted Mineral-Insulated, Metal-Sheathed, Base Metal Thermocouple CableE780 Test Method for Measuring the Insulation Resistance of Mineral-Insulated, Metal-Sheathed Thermocouples andThermocouple Cable at Room TemperatureE839 Test Methods for Sheathed Thermocouples and Sheathed Th
21、ermocouple CableE883 Guide for ReflectedLight PhotomicrographyE1652 Specification for Magnesium Oxide and Aluminum Oxide Powder and Crushable Insulators Used in the Manufacture ofMetal-Sheathed Platinum Resistance Thermometers, Base Metal Thermocouples, and Noble Metal Thermocouples2.2 ANSI Standard
22、:B46.1 Surface Texture42.3 American Welding Society Standard:A5.9 Specification for Corrosion-Resisting Chromium and Chromium-Nickel Steel-Welding Rods and Bare Electrodes53. Terminology3.1 The definitions given in Terminology E344 shall apply to this specification.3.2 Definitions of Terms Specific
23、to This Standard:3.2.1 lot, na quantity of finished MIMS thermocouples manufactured from the same lot of MIMS cable, then assembled andprocessed at the same time under the same controlled production conditions to their required final configuration.4. Ordering Information and Basis of Purchase4.1 The
24、 purchase order documents shall specify the following information:4.1.1 The quantity, length, and nominal diameter of the sheathedMIMS thermocouple,3For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Stand
25、ardsvolume information, refer to the standards Document Summary page on the ASTM website.4Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.5Available from American Welding Society (AWS), 550 NW LeJeune Rd., Miami, FL 33126
26、, http:/www.aws.org.TABLE 1 Dimensions for Style G and U Measuring JunctionsSheath Outside Diameter, A MinimumSheathWall,BMinimumInsulationThickness,CMinimumWireDiameter,DE, Tolerance F, ToleranceNominalTolerance min max min maxmin maxInches0.0400 0.0390 0.0415 0.006 0.004 0.005 0.006 0.020 0.004 0.
27、0210.0625 0.0615 0.0640 0.009 0.005 0.010 0.009 0.032 0.005 0.0320.1250 0.1240 0.1265 0.012 0.012 0.020 0.012 0.062 0.012 0.0630.1875 0.1865 0.1890 0.020 0.022 0.031 0.020 0.093 0.022 0.0950.2500 0.2480 0.2520 0.030 0.024 0.040 0.030 0.125 0.024 0.125MillimetresMillimetres1.016 0.991 1.054 0.15 0.10
28、 0.13 0.15 0.51 0.10 0.531.000 0.975 1.038 0.15 0.10 0.13 0.15 0.51 0.10 0.531.588 1.562 1.626 0.23 0.13 0.25 0.23 0.81 0.13 0.811.500 1.475 1.538 0.23 0.13 0.25 0.23 0.81 0.13 0.813.175 3.150 3.213 0.30 0.30 0.51 0.30 1.57 0.30 1.603.000 2.975 3.038 0.30 0.30 0.51 0.30 1.57 0.30 1.604.763 4.737 4.8
29、01 0.51 0.56 0.79 0.51 2.36 0.56 2.414.500 4.475 4.538 0.51 0.56 0.79 0.51 2.36 0.56 2.416.350 6.299 6.401 0.76 0.61 1.02 0.76 3.18 0.61 3.186.000 5.950 6.050 0.76 0.61 1.02 0.76 3.18 0.61 3.18E235/E235M 1224.1.2 The thermocouple type and tolerance on the initial values of emf versus temperature per
30、 Table 2, if other than standard(see Specification E230), standard,4.1.3 The type of ceramic insulation required, either alumina (Al2O3) or magnesia (MgO),4.1.4 The type of sheath material and other information required (see 5.1.1),4.1.5The style of thermocouple measuring junction,4.1.5 The style of
31、 thermocouple measuring junction (see 1.2),4.1.6 The type of dye-penetrant inspection procedure to be used, and4.1.7 Any deviations from this specification or the referenced specifications.5. Materials and Manufacture5.1 All materials used shall be in accordance with the following requirements:5.1.1
32、 Sheath MaterialsThe sheath material used for the thermocouples described in this specification mustshall meet therequirements of Specification E585/E585M. The purchaser of the thermocouples shall specify only the name of the material(seamless or welded), grade, optional requirements, test report re
33、quired, and ASTM designation.5.1.1.1 The inclusion level of the tubingsheath shall be determined by mounting a 1-in. minimum length of a longitudinalsection of the tubingsheath using Test Methods E45, Microscopical Method A, for examination. The inclusion level shall be lessthan 3 A through D, thin
34、or heavy.5.1.1.2 The grain size of the tubingsheath shall be determined by a specimen taken in accordance with Test Methods E112.Grain size shall be as specified in Table 2Table 3, or finer, as determined by the Comparison Procedure of Test Methods E112.5.1.1.3 Each lot of tubingsheath material used
35、 shall be sampled using Practices A262 as follows. Samples shall be tested byPractice A, and further tested as outlined by Table 1 in Practices A262, where screening tests so indicate. Acceptance levels forthese tests shall be agreed upon between the purchaser and the producer.FIG. 1 Grounded Measur
36、ing Junction, Style GFIG. 2 Ungrounded Measuring Junction, Style UTABLE 2 Tolerances on Initial Values of EMF versus Temperature for MIMS ThermocouplesNOTE 1Tolerances in this table apply to new MIMS thermocouples.NOTE 2Tolerances apply to new material as produced and do not allow for changes in the
37、rmoelectric characteristics of the materials during use. Themagnitude of such changes depends upon such factors as sheath and thermoelement size, temperature, time of exposure, and the environment.NOTE 3Where tolerances are given in percent, the percentage applies to the temperature being measured w
38、hen expressed in degrees Celsius.NOTE 4To determine the tolerance in degrees Fahrenheit, multiply the tolerance in degrees Celsius by 9/5.ThermocoupleTypeTemperature Range TolerancesReference Junction 32F 0CF C Standard Tolerances Special TolerancesF C F CKorN 32 to 2300 0 to 1260 Note 4 The greater
39、 of 62.2C or 60.75 % Note 4 The greater of 61.1C or 60.4 %KA328 to 32 200 to 0 The greater of 62.2C or 62%BAMIMS the thermocouples are normally supplied to meet the tolerances specified in the table for temperatures above 0C. The same materials, however, may not fallwithin the sub-zero tolerances gi
40、ven in the second section of the table. If materials are required to meet the sub-zero limits, the purchase order shall so state. Selectionof materials shall be required.BLittle information is available to justify establishing special tolerances for sub-zero temperatures. Such special sub-zero toler
41、ances, if required, shall be agreed uponbetween the purchaser and the producer.E235/E235M 1235.1.2 ThermoelementThermoelements referred to in this specification shall be Type K or Type N with a tolerance on initialvalues of emf versus temperature specified if other than standard. Thermoelements refe
42、rred to in this specification shall be TypeK or Type N with a standard tolerance on initial values of emf versus temperature as specified in Table 2 unless otherwise specifiedby the purchaser.NOTE1The purchaser may specify an alternative type of thermoelement as designated in Specification E230 by i
43、ndicating this deviation in the orderingdocuments. 1The purchaser may specify an alternative type of thermoelement as designated in Specification E230 by indicating this deviation in theordering documents. The supplier and the purchaser shall then agree upon a tolerance.5.1.3 InsulationThe insulatin
44、g material shall be either magnesia (MgO) or alumina (Al2O3) and shall comply withSpecification E1652 Type 1 material requirements:5.1.3.1 A certified analysis of the composition of the insulating material as supplied to the thermocouple manufacturer shall befurnished to the purchaser. The thermocou
45、ple manufacturer shall be responsible for maintaining the purity withinin the specifiedlimits infinished product within the finished product. specified limits.5.1.4 Welding RodFiller rod material used for welding on the sheath or for welding the end of the thermocoupleclosuresclosed shall comply wit
46、h the requirements of AWS Specification A5.9 for the tubingsheath material specified on theordering documents.5.2 Processing:5.2.1 CleanlinessThe outer surface of the completed thermocouples at the time of delivery shall be free of residues containingnuclear poisons, (such as boron and cadmium compo
47、unds,) or foreign substances, (such as chlorine compounds, strong acids, acidsor bases, oils, greases, or dust) that could become the source of corrosion or chemistry changes in a primary coolant or heat-transfermedium. The use of compounds containing halogens is prohibited for final cleaning is pro
48、hibited. Alcohol, or methyl isobutylketone may be used unless otherwise specified.5.2.2 AnnealingThe sheath of the finished thermocouple shall be solution annealed and shall not be sensitized.6. Inspection and Test Methods6.1 General ProcedureInspect and approve all thermocouples in accordance with
49、the sampling procedures specified in thissection and with inspection requirements stated herein and in referenced specifications.Acceptance of the sample inspection resultsdoes not relieve the thermocouple manufacturer of the responsibility that all thermocouples shall conform to all requirements ofthis specification and the latest issue of the referenced specifications.6.1.1Acceptance of thermocouples manufact
