ASTM E2658-15(2023)

Standard Practices for Verification of Speed for Material Testing Machines

SIGNIFICANCE AND USE
4.1 Material testing requires repeatable and predictable testing machine speed. The speed measuring devices integral to the testing machines may be used for measurement of crosshead speed over a defined range of operation. The accuracy of the speed value shall be traceable to a National or International Standards Laboratory. Practices E2658 provides procedures to verify testing machines, in order that the indicated speed values may be traceable. A key element to having traceability is that the devices used in the verification produce known speed characteristics, and have been calibrated in accordance with adequate calibration standards.  
4.2 Verification of testing machine speed at a minimum consists of either or both of the following options:  
4.2.1 Verifying the capability of the testing machine to move the crosshead at the speed selected.  
4.2.2 Verifying the capability of the testing machine to adequately indicate the speed of the crosshead.  
4.3 Where applicable, determine the testing machine's ramp-to-speed condition. This condition can be significant especially when verifying fast speeds or testing conditions with very short testing durations.  
4.4 This procedure will establish the relationship between the actual crosshead speed and the testing machine indicated speed and or selected setting. It is this relationship that will allow confidence in the reported displacement over time data acquired by the testing machine during use.
Note 1: Many material tests never reach the desired test speed. Unless the actual data from the material test is examined, it is often impossible to know if the test speed has been reached or is repeatable from test to test.
SCOPE
1.1 These practices cover procedures and requirements for the calibration and verification of testing machine speed by means of standard calibration devices. This practice is not intended to be complete purchase specifications for testing machines.  
1.2 These practices apply to the verification of the speed application and measuring systems associated with the testing machine, such as a scale, dial, marked or unmarked recorder chart, digital display, setting, etc. In all cases the buyer/owner/user must designate the speed-measuring system(s) to be verified.  
1.3 These practices give guidance, recommendations, and examples, specific to electro-mechanical testing machines. The practice may also be used to verify actuator speed for hydraulic testing machines.  
1.4 This standard cannot be used to verify cycle counting or frequency related to cyclic fatigue testing applications.  
1.5 Since conversion factors are not required in this practice, either SI units (mm/min), or English [in/min], can be used as the standard.  
1.6 Speed measurement values and or settings on displays/printouts of testing machine data systems-be they instantaneous, delayed, stored, or retransmitted-which are within the Classification criteria listed in Table 1, comply with Practices E2658.  
1.7 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Aug-2023
• ICS: 19.060 - Mechanical testing
• Technical Committee: E28 - Mechanical Testing
• Drafting Committee: E28.01 - Calibration of Mechanical Testing Machines and Apparatus

Relations

• Refers: ASTM E2309-05 - Standard Practices for Verification of Displacement Measuring Systems and Devices Used in Material Testing Machines
• Effective Date: 01-Feb-2005

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E2658 − 15 (Reapproved 2023)
Standard Practices for
Verification of Speed for Material Testing Machines
This standard is issued under the fixed designation E2658; the number immediately following the designation indicates the year of
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. Scope mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.1 These practices cover procedures and requirements for
the calibration and verification of testing machine speed by
2. Referenced Documents
means of standard calibration devices. This practice is not
2.1 ASTM Standards:
intended to be complete purchase specifications for testing
E2309 Practices for Verification of Displacement Measuring
machines.
Systems and Devices Used in Material Testing Machines
1.2 These practices apply to the verification of the speed
application and measuring systems associated with the testing
3. Terminology
machine, such as a scale, dial, marked or unmarked recorder
3.1 Definitions:
chart, digital display, setting, etc. In all cases the buyer/owner/
3.1.1 percent error, n—in the case of a speed measuring
user must designate the speed-measuring system(s) to be
system, the ratio, expressed as a percent, of the error to the
verified.
reference value of the applied speed.
1.3 These practices give guidance, recommendations, and
3.1.1.1 Discussion—The speed, as measured by the testing
examples, specific to electro-mechanical testing machines. The
machine, and the speed, as computed from the readings of the
practice may also be used to verify actuator speed for hydraulic
calibration devices, shall be recorded at each verified speed.
testing machines.
The percent error, shall be calculated from this data as follows:
1.4 This standard cannot be used to verify cycle counting or
Percent Error 5 @~TMsp 2 Refsp!/Refsp# × 100 (1)
frequency related to cyclic fatigue testing applications.
where:
1.5 Since conversion factors are not required in this
TMsp = speed measured by the machine being verified,
practice, either SI units (mm/min), or English [in/min], can be
mm/min [in/min], and
used as the standard.
Refsp = reference value of the measured speed, mm/min
[in/min], as determined by the calibration device.
1.6 Speed measurement values and or settings on displays/
printouts of testing machine data systems-be they
Not all testing machines have available indicated speed
instantaneous, delayed, stored, or retransmitted-which are
values. In such cases, the verification of the testing ma-
within the Classification criteria listed in Table 1, comply with
chine’s speed setting is applicable. The percent error for the
Practices E2658.
testing machine speed settings, shall be calculated as fol-
1.7 This standard does not purport to address all of the lows:
safety concerns, if any, associated with its use. It is the
Percent Error 5 TMsps 2 Refsp /Refsp × 100 (2)
@~ ! #
responsibility of the user of this standard to establish appro-
where:
priate safety, health, and environmental practices and deter-
TMsps = testing machine speed setting, mm/min (in/min),
mine the applicability of regulatory limitations prior to use.
and
1.8 This international standard was developed in accor-
Refsp = reference value of the measured speed, mm/min
dance with internationally recognized principles on standard-
(in/min), as determined by the calibration device.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom- 3.1.2 ramp-to-speed condition, n—during a speed verifica-
tion run, it is the time and or change in displacement required
to achieve a constant speed condition.
These practices are under the jurisdiction of ASTM Committee E28 on
Mechanical Testing and is the direct responsibility of Subcommittee E28.01 on
Calibration of Mechanical Testing Machines and Apparatus. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Sept. 1, 2023. Published September 2023. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 2011. Last previous edition approved in 2015 as E2658–15. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/E2658–15R23. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2658 − 15 (2023)
know if the test speed has been reached or is repeatable from test to test.
3.1.3 reference standards, n—devices used to verify either
the speed of a testing machine or the speed indicated by a
5. Calibration Devices
testing machine.
5.1 Reference standards used for verification of speed
3.1.4 speed measuring system, n—a device or set of devices
measuring systems shall have estimated measurement uncer-
comprising of a speed transducer and associated instrumenta-
tainties. The measurement uncertainty of verification results,
tion or a displacement transducer with associated timer and
contain the combination of the uncertainty of the displacement
instrumentation.
calibration device and time indicating device. The combined
3.1.5 tolerance, n—the allowable deviation from a reference
estimate of uncertainty for the reference standards shall be
value.
equal to or less than ⁄3 the allowable error for the measuring
3.1.6 speed, n—displacement divided by time expressed in
system. The estimated measurement uncertainty of the refer-
terms of millimeters/minute, inches/minute, etc.
ence standards should have a confidence level of 95 % (k=2).
3.1.7 verification speed, n—a speed with traceability de-
5.2 It is recommended that the testing machine have its
rived from national standards of length and time, with a
displacement measuring systems verified in compliance with
specific uncertainty of measurement, which can be applied to
Practices E2309 prior to performing this verification. Often the
speed measuring systems.
same displacement calibration devices can be used to perform
Practices E2309 and this practice. It may be possible to attach
TABLE 1 Classification of Speed Application Measuring Systems
the Displacement Calibration Device one time and perform
B
Classification Resolution Percent Error
both verification practices.
A
% of Reading
Class A ±0.25 ±0.5
5.3 Displacement Calibration Devices:
Class B ±0.5 ±1.0
5.3.1 Digital Linear Scales and Displacement Measuring
Class C ±1.0 ±2.0
Transducers—These devices typically have sufficient resolu-
Class D ±2.5 ±5.0
Class E ±5.0 ±10
tion and accuracy to perform verification of all speed settings.
Class F ±10 ±20
It is important to assess the minimum measurement capability
A
Resolution is not criteria for classification when speed application only, is verified.
of the device. At very slow speeds it may take considerable
B
Percent Error of application or indication of speed.
time to reach an end displacement value that is adequate for the
use of the device.
5.3.1.1 These devices may also have the capability to be
4. Significance and Use
automated.
4.1 Material testing requires repeatable and predictable
5.4 Time Indicating Devices:
testing machine speed. The speed measuring devices integral to
5.4.1 Time pieces such as quartz wrist and stop watches can
the testing machines may be used for measurement of cross-
be used for slower speed settings. The time piece shall have a
head speed over a defined range of operation. The accuracy of
calibration traceable to a national metrology institute. For most
the speed value shall be traceable to a National or International
purposes, a time piece with an accuracy of 60.02% (approxi-
Standards Laboratory. Practices E2658 provides procedures to
mately 2 second in 3 hours) is sufficient. The uncertainty of the
verify testing machines, in order that the indicated speed values
calibration of the time piece shall be at most ⁄3 the accuracy of
may be traceable. A key element to having traceability is that
the time piece and shall not significantly contribute to the
the devices used in the verification produce known speed
uncertainty of the speed measurement. See NIST Special
characteristics, and have been calibrated in accordance with
Publication 960-12. With automated computer software, ac-
adequate calibration standards.
curacies of 60.01 seconds may be achieved. However, care
4.2 Verification of testing machine speed at a minimum
must be taken in designing such systems to avoid errors due to
consists of either or both of the following options:
things such as timer resolution, programming language
4.2.1 Verifying the capability of the testing machine to
limitations, competing interrupts and processes, etc. Third
move the crosshead at the speed selected.
party software is available to track and adjust the computer
4.2.2 Verifying the capability of the testing machine to
clock referenced to NIST.
adequately indicate the speed of the crosshead.
4.3 Where applicable, determine the testing machine’s 6. System Verification
ramp-to-speed condition. This condition can be significant
6.1 Speed measuring systems shall be verified as a system
especially when verifying fast speeds or testing conditions with
with the speed sensing and measuring devices in place and
very short testing durations.
operating as in actual use.
4.4 This procedure will establish the relationship between
6.2 System verification is invalid if the speed sensing
the actual crosshead speed and the testing machine indicated
devices are removed and checked independently of the testing
speed and or selected setting. It is this relationship that will
machine.
allow confidence in the reported displacement over time data
acquired by the testing machine during use.
NOTE 1—Many material tests never reach the desired test speed. Unless Gust, J.C., Graham, R.M., Lombardi, M.A. Special Publication 960-12 Stop-
the actual data from the material test is examined, it is often impossible to watch and Timer Calibrations National Institute of Standards and Technology 2004
E2658 − 15 (2023)
6.3 The verification shall consist of at least two verification and very time consuming to verify every selectable setting
runs of speed derived data per selected testing machine speed available with testing machines. Additionally, it is often
setting. impossible to adequately verify the fastest speed selections
6.3.1 If the initial verification run produces any percent because displacement calibration devices are typically not long
error values outside applicable specifications, the “as found” enough to accommodate the displacement necessary. For these
data may be reported and may be used in accordance with reasons, at a minimum, speeds most commonly used should be
applicable quality control programs. selected for verification. A minimum of two runs of verification
6.3.2 Adjustments may be made to improve the accuracy of data for each speed is required.
the system. They shall be followed by one additional verifica- 8.1.1 In some cases a testing machine might only be used at
tion run, and issuance of a new verification report. Typically, one speed with one clutch selected. In such a case only one
making adjustments to improve testing machine speed will speed with two runs of data are all that is required to meet this
influence all speed settings. If an adjustment is made, all tested standard.
speeds must be re-verified unless it can be demonstrated that
8.2 Many testing machines have multiple clutch selections.
the adjustment did not affect other speed settings.
If the testing machine is used with multiple clutch settings,
6.3.3 Quality control programs may require evidence of
speeds for each clutch setting shall be verified even if the
repeatability, reproducibility and reversibility. In such cases it
selected speed is the same as a selected speed verified with a
is recommended that a minimum of one speed be verified for
different clutch setting.
repeatability, reproducibility, and reversibility.
8.3 In selecting speeds to be verified, consideration of the
6.4 The testing machine is verified with the crosshead
total displacement and time must be considered. The total
configured to free run with no specimen installed.
displacement must be great enough to allow for the displace-
ment calibration device’s measurement uncertainty. If the
NOTE 2—Testing machine compliance under loading conditions may
introduce small errors in the displacement measurement data during actual calibration devices are automated, time is not as critical to the
materials testing. This error is considered insignificant relative to this
overall measurement uncertainty. But, if a manual Start and
verification. There are also testing machines where the crosshead speed
Stop method is employed, the duration of the verification run
slows when force is applied. In such cases where it is necessary to verify
must be long enough to minimize error due to human action.
speed of the testing machine under loaded conditions, higher accuracy
The manual Start and Stop method also requires that the total
displacement calibration devices such as laser interferometer measuring
systems, or extensometer type displacement reference standards must be displacement and duration of the verification run be long
used due to the very small displacements being verified.
enough to start beyond the ramp to speed condition. See
Appendix X1.
7. Methods of Verification
8.4 It is not normal to experience a difference in the speed
7.1 Start and Stop Method:
indication of the testing machine when the crosshead moves in
7.1.1 This method requires that a set of starting and stopping
the opposite direction. However, gravity may contribute to a
displacement and time readings be recorded from the displace-
difference in the ramp to speed condition when the crosshead
ment and time calibration devices.
is operated in the descending mode. The testing machine
7.1.2 In order to obtain data within expected tolerances an
should be verified in the mode of operation normally used
assessment of the ramp-to-speed condition may be necessary
during testing.
so the test run can be started after the crosshead has reached a
constant speed condition. 9. Preliminary Procedure
7.1.3 It is best to have testing machine software that can
9.1 Alignment:
easily acquire and report displacement and time data during the
9.1.1 When attaching the displacement calibration device, it
verification run for each sel
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