ASTM E2624-09
(Practice)Standard Practice for Torque Calibration of Testing Machines and Devices
Standard Practice for Torque Calibration of Testing Machines and Devices
SIGNIFICANCE AND USE
Testing machines that apply and indicate torque are used in many industries, in many ways. They may be used in a research laboratory to measure material properties, and in a production line to qualify a product for shipment. No matter what the end use of the machine may be, it is necessary for users to know the amount of torque that is applied, and that the accuracy of the torque value is traceable to the National Standards. This standard provides a procedure to verify these machines and devices, in order that the indicated torque values may be traceable. A key element to having traceability is that the devices used in the calibration produce known torque characteristics, and have been calibrated in accordance with Practice E 2428.
This standard may be used by those using, those manufacturing, and those providing calibration service for torque capable testing machines or devices and related instrumentation.
SCOPE
1.1 This practice covers procedures and requirements for the calibration of torque for static and quasi-static torque capable testing machines or devices. These may, or may not, have torque indicating systems and include those devices used for the calibration of hand torque tools. Testing machines may be calibrated by one of the three following methods or combination thereof:
1.1.1 Use of standard weights and lever arms.
1.1.2 Use of elastic torque measuring devices.
1.1.3 Use of elastic force measuring devices and lever arms.
1.1.4 Any of the methods require a specific uncertainty of measurement and a traceability derived from national standards of mass and length.
1.2 The procedures of 1.1.1, 1.1.2, and 1.1.3 apply to the calibration of the torque-indicating systems associated with the testing machine, such as a scale, dial, marked or unmarked recorder chart, digital display, etc. In all cases the buyer/owner/user must designate the torque-indicating system(s) to be calibrated and included in the report.
1.3 Since conversion factors are not required in this practice, either english units, metric units, or SI units can be used as the standard.
1.4 Torque values indicated on displays/printouts of testing machine data systems—be they instantaneous, delayed, stored, or retransmitted—which are Calibrated with provisions of 1.1.1, 1.1.2 or 1.1.3 or a combination thereof, and are within the ±1 % of reading accuracy requirement, comply with this practice.
1.5 The following applies to all specified limits in this standard: For purposes of determining conformance with these specifications, an observed value or a calculated value shall be rounded “to the nearest unit” in the last right-hand digit used in expressing the specification limit, in accordance with the rounding method of Practice E 29, for Using Significant Digits in Test Data to Determine Conformance with Specifications.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E2624 − 09
StandardPractice for
1
Torque Calibration of Testing Machines and Devices
This standard is issued under the fixed designation E2624; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.6 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
1.1 This practice covers procedures and requirements for
responsibility of the user of this standard to establish appro-
the calibration of torque for static and quasi-static torque
priate safety and health practices and determine the applica-
capable testing machines or devices. These may, or may not,
bility of regulatory limitations prior to use.
have torque indicating systems and include those devices used
for the calibration of hand torque tools. Testing machines may
2. Referenced Documents
be calibrated by one of the three following methods or
combination thereof: 2
2.1 ASTM Standards:
1.1.1 Use of standard weights and lever arms.
E6Terminology Relating to Methods of MechanicalTesting
1.1.2 Use of elastic torque measuring devices.
E29Practice for Using Significant Digits in Test Data to
1.1.3 Useofelasticforcemeasuringdevicesandleverarms.
Determine Conformance with Specifications
1.1.4 Any of the methods require a specific uncertainty of
E74Practice of Calibration of Force-Measuring Instruments
measurementandatraceabilityderivedfromnationalstandards
for Verifying the Force Indication of Testing Machines
of mass and length.
E2428Practice for Calibration of Torque-Measuring Instru-
1.2 The procedures of 1.1.1, 1.1.2, and 1.1.3 apply to the
ments for Verifying the Torque Indication of Torque
calibrationofthetorque-indicatingsystemsassociatedwiththe Testing Machines
testing machine, such as a scale, dial, marked or unmarked
2.2 NIST Technical Notes:
recorderchart,digitaldisplay,etc.Inallcasesthebuyer/owner/
NIST Technical Note 1297Guidelines for Evaluating and
user must designate the torque-indicating system(s) to be
Expressing the Uncertainty of NIST Measurement Re-
calibrated and included in the report. 3
sults
1.3 Since conversion factors are not required in this
practice, either english units, metric units, or SI units can be
3. Terminology
used as the standard.
3.1 Definitions:
1.4 Torque values indicated on displays/printouts of testing
3.1.1 accuracy—accuracy is defined in Terminology E6.
machine data systems—be they instantaneous, delayed, stored,
3.1.1.1 Discussion—Atestingmachineissaidtobeaccurate
or retransmitted—which are Calibrated with provisions of
if the indicated torque is within the specified permissible
1.1.1, 1.1.2 or 1.1.3 or a combination thereof, and are within
variation from the actual torque in these methods the word
the 61% of reading accuracy requirement, comply with this
“accurate” applied to a testing machine is used without
practice.
numerical values, for example, “An accurate testing machine
1.5 The following applies to all specified limits in this
was used for the investigation.” The accuracy of a testing
standard: For purposes of determining conformance with these
machine should not be confused with sensitivity. For example,
specifications, an observed value or a calculated value shall be
a testing machine might be very sensitive; that is, it might
rounded“tothenearestunit”inthelastright-handdigitusedin
indicate quickly and definitely small changes in torque, but
expressing the specification limit, in accordance with the
nevertheless, be very inaccurate. On the other hand, the
rounding method of Practice E29, for Using Significant Digits
accuracy of the results is in general limited by the sensitivity.
in Test Data to Determine Conformance with Specifications.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
1
ThispracticeisunderthejurisdictionofASTMCommitteeE28onMechanical contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Testing and is the direct responsibility of Subcommittee E28.01 on Calibration of Standards volume information, refer to the standard’s Document Summary page on
Mechanical Testing Machines and Apparatus. the ASTM website.
3
Current edition approved April 1, 2009. Published May 2009. DOI: 10.1520/ Available from National Institute of Standards and Technology (NIST), 100
E2624-09. Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http://www.nist.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
E2624 − 09
3.1.2 calibrated range of torque—in the case of testin
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.