ASTM_E_1652_-_15.pdf

Designation:E165215Standard Specification forMagnesium Oxide and Aluminum Oxide Powder andCrushable Insulators Used in the Manufacture of Base MetalThermocouples,Metal-Sheathed Platinum ResistanceThermometers,and Noble Metal Thermocouples1This standard is issued under the fixed designation E1652;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This specification covers the requirements for magne-sium oxide(MgO)and aluminum oxide(Al2O3)powders andcrushable insulators used to manufacture base metalthermocouples,metal-sheathed platinum resistance thermom-eters(PRTs),noble metal thermocouples,and their respectivecables.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.3 This 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 limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2B329 Test Method for Apparent Density of Metal Powdersand Compounds Using the Scott VolumeterC809 Test Methods for Chemical,Mass Spectrometric,andSpectrochemical Analysis of Nuclear-Grade AluminumOxide and AluminumOxide-Boron Carbide CompositePelletsC832 Test Method of Measuring Thermal Expansion andCreep of Refractories Under LoadD2766 Test Method for Specific Heat of Liquids and SolidsE228 Test Method for Linear Thermal Expansion of SolidMaterials With a Push-Rod DilatometerE235 Specification for Thermocouples,Sheathed,Type Kand Type N,for Nuclear or for Other High-ReliabilityApplicationsE344 Terminology Relating to Thermometry and Hydrom-etryE585/E585M SpecificationforCompactedMineral-Insulated,Metal-Sheathed,Base Metal ThermocoupleCableE1137/E1137M Specification for Industrial Platinum Resis-tance ThermometersE1225 Test Method for Thermal Conductivity of SolidsUsing the Guarded-Comparative-Longitudinal Heat FlowTechniqueE2181/E2181M Specification for Compacted Mineral-Insulated,Metal-Sheathed,Noble Metal Thermocouplesand Thermocouple Cable3.Terminology3.1 The definitions given in Terminology E344 shall applyto this specification.4.Significance and Use4.1 Magnesium oxide and aluminum oxide are used toelectrically isolate and mechanically support the thermoele-ments of a thermocouple(see Specifications E235,E585/E585M,and E2181/E2181M)and the connecting wires of aPRT(see Specification E1137/E1137M)within a metal sheath.The metal sheath is typically reduced in diameter to compactthe oxide powder or crushable oxide insulators around thethermoelements or wires.4.2 In order to be suitable for this purpose,the materialsshall meet certain criteria for purity and for mechanical anddimensional characteristics.Material that does not meet thepurity criteria may cause premature failure of the sensor.4.3 Use of this specification for the procurement of powderand crushable insulators will help to ensure that the productobtained is suitable for the intended purpose.4.4 Useful information about alumina and magnesia is givenin the appendixes.1This specification is under the jurisdiction of ASTM Committee E20 onTemperature Measurement and is the direct responsibility of Subcommittee E20.04on Thermocouples.Current edition approved Nov.1,2015.Published November 2015.Originallyapproved in 1995.Last previous edition approved in 2014 as E1652 14a.DOI:10.1520/E1652-15.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.Classification5.1 The purchaser shall specify the appropriate Material andType from 5.2 through 5.6 below.5.2 MgO Type 1 in accordance with Table 1.5.3 Al2O3Type 1 in accordance with Table 1.5.4MgO Type 1P in accordance with Table 2.5.5 Al2O3Type 1P in accordance with Table 2.5.6 MgO Type 2 in accordance with Table 3.NOTE1There is no corresponding Al2O3Type 2 designation at thistime.5.7 The final product shall be chemically analyzed usingappropriate methods listed in 9.1.Major impurities shall notexceed the limits indicated in Table 1 through Table 3 for theappropriate grade.Any detected impurity with a concentrationgreater than 0.001%(mass)shall be reported to the purchaser.6.Ordering Information6.1 The purchaser shall specify the following when order-ing:6.1.1 Material and Type in accordance with Section 5.6.1.2 Insulator Outside Diameter.6.1.3 Hole Diameter.6.1.4 Number of Holes.6.1.5 Hole Pattern.6.1.6 Length.6.1.7 Parti