1、Designation:E262409Standard Practice forTorque Calibration of Testing Machines and Devices1This standard is issued under the fixed designation E2624;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number i
2、n parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice covers procedures and requirements forthe calibration of torque for static and quasi-static torquecapable testing machines or devices
3、.These may,or may not,have torque indicating systems and include those devices usedfor the calibration of hand torque tools.Testing machines maybe calibrated by one of the three following methods orcombination thereof:1.1.1 Use of standard weights and lever arms.1.1.2 Use of elastic torque measuring
4、 devices.1.1.3 Use of elastic force measuring devices and lever arms.1.1.4 Any of the methods require a specific uncertainty ofmeasurement and a traceability derived from national standardsof mass and length.1.2 The procedures of 1.1.1,1.1.2,and 1.1.3 apply to thecalibration of the torque-indicating
5、 systems associated with thetesting machine,such as a scale,dial,marked or unmarkedrecorder chart,digital display,etc.In all cases the buyer/owner/user must designate the torque-indicating system(s)to becalibrated and included in the report.1.3 Since conversion factors are not required in thispracti
6、ce,either english units,metric units,or SI units can beused as the standard.1.4 Torque values indicated on displays/printouts of testingmachine data systemsbe they instantaneous,delayed,stored,or retransmittedwhich are Calibrated with provisions of1.1.1,1.1.2 or 1.1.3 or a combination thereof,and ar
7、e withinthe 61%of reading accuracy requirement,comply with thispractice.1.5 The following applies to all specified limits in thisstandard:For purposes of determining conformance with thesespecifications,an observed value or a calculated value shall berounded“to the nearest unit”in the last right-han
8、d digit used inexpressing the specification limit,in accordance with therounding method of Practice E29,for Using Significant Digitsin Test Data to Determine Conformance with Specifications.1.6 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is t
9、heresponsibility 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:2E6 Terminology Relating to Methods of Mechanical TestingE29 Practice for Using Signifi
10、cant Digits in Test Data toDetermine Conformance with SpecificationsE74 Practice of Calibration of Force-Measuring Instrumentsfor Verifying the Force Indication of Testing MachinesE2428 Practice for Calibration of Torque-Measuring Instru-ments for Verifying the Torque Indication of TorqueTesting Mac
11、hines2.2 NIST Technical Notes:NIST Technical Note 1297 Guidelines for Evaluating andExpressing the Uncertainty of NIST Measurement Re-sults33.Terminology3.1 Definitions:3.1.1 accuracyaccuracy is defined in Terminology E6.3.1.1.1 DiscussionAtesting machine is said to be accurateif the indicated torqu
12、e is within the specified permissiblevariation from the actual torque in these methods the word“accurate”applied to a testing machine is used withoutnumerical values,for example,“An accurate testing machinewas used for the investigation.”The accuracy of a testingmachine should not be confused with s
13、ensitivity.For example,a testing machine might be very sensitive;that is,it mightindicate quickly and definitely small changes in torque,butnevertheless,be very inaccurate.On the other hand,theaccuracy of the results is in general limited by the sensitivity.1This practice is under the jurisdiction o
14、fASTM Committee E28 on MechanicalTesting and is the direct responsibility of Subcommittee E28.01 on Calibration ofMechanical Testing Machines and Apparatus.Current edition approved April 1,2009.Published May 2009.DOI:10.1520/E2624-09.2For referenced ASTM standards,visit the ASTM website,www.astm.org
15、,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from National Institute of Standards and Technology(NIST),100Bureau Dr.,Stop 1070,Gaithersburg,MD 20899-1070,http:/www.ni
16、st.gov.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.2 calibrated range of torquein the case of testingmachines,the range of indicated torque for which the testingmachine gives results within the permissible variations speci-fied.3.1.3 calibration torquea torque with traceability derivedfrom national standards of mass and length and of specificuncertainty of measurement,which can be applied to torquemeasuring devices.3.1.4 capac
