ASTM_E_2820_-_13.pdf

Designation:E282013Standard Test Method forEvaluating Thermal EMF Properties of Base-MetalThermocouple Connectors1This standard is issued under the fixed designation E2820;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 standard describes a thermal emf test method forbase-metal thermocouple connectors including Types E,J,K,N and T.Standard connectors such as found in SpecificationsE1129/E1129M and E1684 as well as non-standard connectorconfigurations and connector components can be evaluatedusing this method.1.2 The measured emf is reported as an equivalent tempera-ture deviation or error relative to a reference thermocouple ofthe same type.This method can be used to verify deviationsintroduced by the connector greater than or equal to 1C.1.3 The connector is tested with thermocouple contactsaxially aligned with a temperature gradient using a specifiedthermal boundary condition.The actual temperature differencedeveloped across the connector and corresponding error willdepend on the connector design.1.4 Connector contacts are often fabricated from raw mate-rials having temperature-emf relationships in accordance withSpecification E230.However,verifying Specification E230tolerances is not within the scope of this method.1.5 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.6 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:2E220 Test Method for Calibration of Thermocouples ByComparison TechniquesE230 Specification and Temperature-Electromotive Force(EMF)Tables for Standardized ThermocouplesE344 Terminology Relating to Thermometry and Hydrom-etryE563 Practice for Preparation and Use of an Ice-Point Bathas a Reference TemperatureE1129/E1129M Specification for Thermocouple ConnectorsE1684 Specification for Miniature Thermocouple Connec-torsE2488 Guide for the Preparation and Evaluation of LiquidBaths Used for Temperature Calibration by Comparison3.Terminology3.1 DefinitionsThe definitions given in Terminology E344apply to the terms used in this standard.4.Summary of Test Method4.1 The connector is tested as part of a thermocouple circuitand compared to a reference thermocouple of the same typeand material lot.4.2 Measurements are made while the connector is sub-jected to a temperature gradient established by a specifiedboundary condition.4.3 Performance is evaluated at a fixed position within adry-well furnace or stirred liquid bath(Method 1 or 2Arespectively)or variable position within a stirred liquid bath(Method 2B).The latter method can be used to survey theconnector to identify a position within the thermal gradient thatproduces a maximum output deviation.4.4 Results are interpreted relative to the properties of thereference thermocouple.5.Significance and Use5.1 A thermocouple connector,exposed to a temperaturedifference,contributes to the output of a thermocouple circuit.The output uncertainty allocated to the connector depends onthe connector design and temperature gradient.5.2 Connector performance can be classified based on theresults of this method and used as part of a componentspecification.1This test method is under the jurisdiction of ASTM Committee E20 onTemperature Measurement and is the direct responsibility of Subcommittee E20.04on Thermocouples.Current edition approved May 1,2013.Published July 2013 Originally approvedin 2011.Last previous edition approved in 2011 as E282011.DOI:10.1520/E282013.2For 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 5.3 The method can be used as an engineering tool forevaluating different connector designs tested under similarthermal conditions.6.Apparatus6.1 The apparatus includes a temperature source,thermo-couple readout device or voltmeter and ice-bath as shown inFig.1 and Fig.2.An ice-bath is needed only if the readout doesnot provide cold junction compensation.6.2 The thermocouple readout device or voltmeter shallhave two or more channels and have equivalent temperatureresolution of at least 0.1C.The difference between channelsshall not exceed the equivalent of 0.1C when supplied withthe same voltage input.6.3 The temperature source heats the measuring junctionsand produces a temp