ASTM E1319-98(2014)
(Guide)Standard Guide for High-Temperature Static Strain Measurement
Standard Guide for High-Temperature Static Strain Measurement
SIGNIFICANCE AND USE
4.1 The use of this guide is voluntary and is intended for use as a procedures guide for selection and application of specific types of strain gages for high-temperature installations. No attempt is made to restrict the type of strain gage types or concepts to be chosen by the user. The provisions of this guide may be invoked in specifications and procedures by specifying those which shall be considered mandatory for the purpose of the specific application. When so invoked, the user shall include in the work statement a notation that provisions of this guide shown as recommendation shall be considered mandatory for the purposes of the specification or procedure concerned, and shall include a statement of any exceptions to or modifications of the affected provisions of this guide.
SCOPE
1.1 This guide covers the selection and application of strain gages for the measurement of static strain up to and including the temperature range from 425 to 650°C (800 to 1200°F). This guide reflects some current state-of-the-art techniques in high temperature strain measurement, and will be expanded and updated as new technology develops.
1.2 This guide assumes that the user is familiar with the use of bonded strain gages and associated signal conditioning and instrumentation as discussed in (1) and (2). 2 The strain measuring systems described are those that have proven effective in the temperature range of interest and were available at the time of issue of this guide. It is not the intent of this guide to limit the user to one of the gage types described nor is it the intent to specify the type of system to be used for a specific application. However, in using any strain measuring system including those described, the proposer must be able to demonstrate the capability of the proposed system to meet the selection criteria provided in Section 5 and the needs of the specific application.
1.3 The devices and techniques described in this guide may be applicable at temperatures above and below the range noted, and for making dynamic strain measurements at high temperatures with proper precautions. The gage manufacturer should be consulted for recommendations and details of such applications.
1.4 The references are a part of this guide to the extent specified in the text.
1.5 The values stated in metric (SI) units are to be regarded as the standard. The values given in parentheses are for informational purposes only.
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
Buy Standard
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: E1319 − 98 (Reapproved 2014)
Standard Guide for
High-Temperature Static Strain Measurement
This standard is issued under the fixed designation E1319; 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 priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
1.1 This guide covers the selection and application of strain
gages for the measurement of static strain up to and including
2. Referenced Documents
thetemperaturerangefrom425to650°C(800to1200°F).This
2.1 ASTM Standards:
guide reflects some current state-of-the-art techniques in high
E6 Terminology Relating to Methods of Mechanical Testing
temperature strain measurement, and will be expanded and
updated as new technology develops.
3. Terminology
1.2 This guide assumes that the user is familiar with the use
3.1 Definitions:
of bonded strain gages and associated signal conditioning and
2 3.1.1 Refer to Terminology E6 for definitions of terms
instrumentation as discussed in (1) and (2). The strain
relating to stress and strain.
measuring systems described are those that have proven
3.2 Definitions of Terms Specific to This Standard:
effectiveinthetemperaturerangeofinterestandwereavailable
3.2.1 Terms pertinent to this guide are described as follows:
atthetimeofissueofthisguide.Itisnottheintentofthisguide
3.2.2 capacitive strain gage—a strain gage whose response
to limit the user to one of the gage types described nor is it the
to strain is a change in electrical capacitance which is predict-
intent to specify the type of system to be used for a specific
ably related to that strain.
application. However, in using any strain measuring system
3.2.3 conditioning circuit—a circuit or instrument subsys-
including those described, the proposer must be able to
tem that applies excitation to a strain gage, detects an electrical
demonstrate the capability of the proposed system to meet the
change in the strain gage, and provides a means for converting
selection criteria provided in Section 5 and the needs of the
this change to an output that is related to strain in the test
specific application.
article.
1.3 The devices and techniques described in this guide may
3.2.3.1 Discussion—The conditioning circuit may include
beapplicableattemperaturesaboveandbelowtherangenoted,
one or more of the following: bridge completion circuit, signal
and for making dynamic strain measurements at high tempera-
amplification, zero adjustment, excitation adjustment,
tures with proper precautions. The gage manufacturer should
calibration, and gain (span) adjustment.
be consulted for recommendations and details of such appli-
3.2.4 compensating gage—a gage element that is subject to
cations.
the same environment as the active gage element, and which is
1.4 The references are a part of this guide to the extent
placed in the adjacent leg of a Wheatstone bridge to provide
specified in the text.
thermal, pressure, or other compensation in the strain gage
1.5 The values stated in metric (SI) units are to be regarded
system.
as the standard. The values given in parentheses are for
3.2.5 electrical simulation—a method of calibration
informational purposes only.
whereby a known voltage is generated at the input of an
1.6 This standard does not purport to address all of the amplifier, equivalent to the voltage produced by a specific
safety concerns, if any, associated with its use. It is the
amount of strain.
responsibility of the user of this standard to establish appro-
3.2.6 free filament gage—a resistive strain gage made from
a continuous wire or foil filament which is fixed to the test
article along the entire length of the gage, and which is
This guide is under the jurisdiction of ASTM Committee E28 on Mechanical
supplied without a permanent matrix.
Testing and is the direct responsibility of Subcommittee E28.01 on Calibration of
Mechanical Testing Machines and Apparatus.
Current edition approved April 15, 2014. Published August 2014. Originally
approved in 1989. Last previous edition approved in 2009 as E1319 - 98 (2009). For referenced ASTM standards, visit the ASTM website, www.astm.org, or
DOI: 10.1520/E1319-98R14. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
The boldface numbers in parentheses refer to the list of references at the end of Standards volume information, refer to the standard’s Document Summary page on
this guide. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E1319 − 98 (2014)
3.2.7 gage factor—the ratio between the unit change of is the peak-to-peak value of a cyclic phenomenon, without
strain gage resistance due to strain and the measurement. reference to a constant zero or reference value (Fig. 1).
3.2.7.1 Discussion—The gage factor is dimensionless and is
3.2.17 test article—an item to which a strain gage system is
expressed as follows:
installed for the purpose of measuring strain in that item.
R 2 R L 2 L ∆R
3.2.18 thermal compensation—the process by which the
o o
K 5 / 5 /ε (1)
R L R
o o o thermaloutputofagagesystemiscounteractedthroughtheuse
of one or more supplementary devices, such as a thermocouple
where:
or compensating gage.
K = gage factor,
3.2.18.1 Discussion—The counteraction may be integral to
R = strain gage resistance at test strain,
the gage system or may be accomplished by data processing
R = strain gage resistance at zero or reference strain,
o
methods, or both.
L = test structure length under the strain gage at test
strain, 3.2.19 thermal output—the reversible part of the tempera-
L = test structure length under the strain gage at zero or ture induced indicated strain of a strain gage installed on an
o
reference strain, unrestrained test specimen when exposed to a change in
∆R = change in strain gage resistance when strain is
temperature.
changed from zero (or reference strain) to test strain,
3.2.20 thermaloutput-unmounted—thereversiblepartofthe
and
temperature induced indicated strain of an unmounted strain
L2L
ε = o
gage when exposed to a change in temperature.
mechanical strain
L
o
3.2.8 integral lead wire—a lead wire or portion of a lead
4. Significance and Use
wire that is furnished by a gage manufacturer as part of the
4.1 Theuseofthisguideisvoluntaryandisintendedforuse
gage assembly.
as a procedures guide for selection and application of specific
3.2.9 linearity—the value measured as the maximum devia-
types of strain gages for high-temperature installations. No
tion between an actual instrument reading and the reading
attempt is made to restrict the type of strain gage types or
predicted by a straight line drawn between upper and lower
concepts to be chosen by the user. The provisions of this guide
calibration points, usually expressed as a percent of the full
may be invoked in specifications and procedures by specifying
scale of the sensor range.
those which shall be considered mandatory for the purpose of
3.2.10 leadwire—aconductorusedtoconnectasensortoits
the specific application. When so invoked, the user shall
instrumentation.
include in the work statement a notation that provisions of this
guide shown as recommendation shall be considered manda-
3.2.11 matrix—an electrically nonconductive layer of mate-
tory for the purposes of the specification or procedure
rial used to support a strain gage grid.
concerned, and shall include a statement of any exceptions to
3.2.11.1 Discussion— The two main functions of a matrix
or modifications of the affected provisions of this guide.
aretoactasanaidforbondingthestraingagetoastructureand
as an electrically insulating layer in cases where the structure
5. Gage Selection Criteria
is electrically conductive.
5.1 The factors listed in this section must be considered
3.2.12 resistive strain gage—a strain gage whose response
when selecting a strain gage system for use in the temperature
to strain is a change in electrical resistance that is predictably
range specified in 1.1. It is recognized that no gage may have
related to that strain.
all of the desired capabilities to meet all requirements of a
3.2.13 shunt calibration—a method of calibration whereby
a resistor or capacitor of known value is placed electrically in
parallel with another resistor or capacitor in a circuit, causing
a calculable change in the total resistance or capacitance that is
predictably related to a specific amount of strain.
3.2.14 strain, linear—theunitelongationinducedinaspeci-
men either by a stress field (mechanical strain) or by a
temperature change (thermal expansion).
3.2.15 strain gage system—the sum total of all components
used to obtain a strain measurement.
3.2.15.1 Discussion—May include a strain gage; a means of
attaching the strain gage to the test articles; lead wires; splices;
lead-wireattachments;signal-conditioningandread-outinstru-
mentation; data-logging system; calibration and control sys-
tem; environmental protection; or any combination of these
and other elements required for the tests.
3.2.16 static strain—a strain that is measured relative to a
constant reference value, as opposed to dynamic strain, which FIG. 1 Relationship Between Static and Dynamic Strain
E1319 − 98 (2014)
particulartest.Theriskofcompromisingcertaintestobjectives demonstrated; if multiple tests are required on the same test
must be evaluated, and some test objectives may have to be article, the capability and effect of gage replacement must also
modified to match the capabilities of the available gage be established.
selected. Guidelines for this evaluation are provided in Section
5.4 Strain Rate—The time response of the candidate gage
9.
system must be adequate to meet test requirements if rapid
changes of load are anticipated. It may be necessary to design
5.2 Operating Temperature:
the loading rate of the test to accommodate limitations of the
5.2.1 Isothermal Tests—Stability of the reference value with
strain measurement system selected.
respect to time is essential when tests are to be made at
constant temperature. The stability of the candidate gage
5.5 Environment—Some gages are limited to specific oper-
system at the specified temperature must be such that any shift
ating environments and therefore, the gage system selected
that occurs in the reference value is tolerable for the duration
must be capable of withstanding the environment in which it
of the test.
will operate. Such limitations must be carefully considered
5.2.2 Thermal Compensation and Transients—The ad- when selecting the gage system to be used. Factors such as
equacy of the thermal compensation must be considered when pressure, vibration, radiation, magnetic fields, humidity, etc.,
the measurement of strain during a thermal transient is re- must be considered. The ambient and test environments of the
quired. Thermal output is a function of temperature, thus its elements of the strain gage system must be considered in the
value at a temperature depends not only on temperature, but on selection of lead wires, connectors, instrumentation, and seals
the temperature history followed in reaching that temperature. (when required).
Ifsignificanthysteresisinthethermalresponseispresent,large
5.6 Strain Range:
errors or uncertainties can result. This is especially true when
5.6.1 Total Strain Range—The maximum strain ranges of
the calibration procedure used to characterize the thermal
the candidate gage types must be defined and must be adequate
output does not accurately reflect the temperature sequence to
for the test. Mechanical strain attenuators, when permissible,
which the gages will be exposed during testing. If the response
may be added to extend the strain range of a given strain gage
time of the compensation is exceeded, the resulting uncertainty
system, subject to the limitation of 5.6.2.
mustbeconsidered.Theabilityofthegagesystemtowithstand
5.6.2 Resolution—The ability of the candidate gage to
the transient without a detrimental shift of the reference value
measure small increments of strain within the total strain range
must be verified. This is true whether or not strain is measured
should be compared with the incremental strain measurement
during the transient. Any gage factor change as a function of
requirements of the test. When mechanical strain attenuators
temperature change must also be considered.
are used, the resulting loss of resolution must be considered.
5.2.3 Precalibration:
5.7 Strain Gradient—The gage length of the candidate gage
5.2.3.1 Thermal output calibration on the structure is usu-
establishes the length over which the unit strain is averaged.
ally not possible and precalibration of gages on a similar
This factor must be considered.
material is necessary. However, variations of up to 0.5 ppm/°F
5.8 Uncertainty Factor—Uncertainty information that is
are possible within a material. Often, rolling direction will
available from the manufacturer must be considered, in con-
influence thermal expansion coefficient.
junction with conditions which are unique to the test, in order
5.2.3.2 Precalibration of resistive or capacitive strain gages
to estimate the total uncertainty.
is performed using a calibration fixture made from material
similar to the test article. The calibration fixture must be made 5.9 Space Requirements—If space on or adjacent to the test
to precisely fit the gage, especially if curvature is involved.
articleislimited,thespacerequirementsforthecompletestrain
Experience has shown mating parts must be lapped together to gage system may be a critical consideration in determining the
provide uniform clamping pressure around the periphery of the
suitability of a particular gage system. Working space for
gage weld area. installation of the system may also be limited and must also be
5.2.3.3 The calibration test should be repeated to ensure considered. Space adjacent to the installed strain gage should
be provided for installation of room-temperature strain gages
precise duplication of the calibration. Zero return should also
repeat exactly. If calibration data does not repeat; either the required for making in-place calibrations.
calibration setup or the gages are faulty.
5.10 Effects of the Strain Gage on the Test Article—In most
5.2.4 Post Test Calibration:
cases the reinforcing effect of the strain gage on the test article
5.2.4.1 A more precise thermal output calibration can be
is negligible, particularly in the case of capacitance gages
achieved
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E1319 − 98 (Reapproved 2009) E1319 − 98 (Reapproved 2014)
Standard Guide for
High-Temperature Static Strain Measurement
This standard is issued under the fixed designation E1319; 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
1.1 This guide covers the selection and application of strain gages for the measurement of static strain up to and including the
temperature range from 425 to 650°C (800 to 1200°F). This guide reflects some current state-of-the-art techniques in high
temperature strain measurement, and will be expanded and updated as new technology develops.
1.2 This practice assumes that the user is familiar with the use of bonded strain gages and associated signal conditioning and
instrumentation as discussed in Refs. (1) and (2). The strain measuring systems described are those that have proven effective in
the temperature range of interest and were available at the time of issue of this practice. It is not the intent of this practice to limit
the user to one of the gage types described nor is it the intent to specify the type of system to be used for a specific application.
However, in using any strain measuring system including those described, the proposer must be able to demonstrate the capability
of the proposed system to meet the selection criteria provided in Section 5 and the needs of the specific application.
1.3 The devices and techniques described in this practice may be applicable at temperatures above and below the range noted,
and for making dynamic strain measurements at high temperatures with proper precautions. The gage manufacturer should be
consulted for recommendations and details of such applications.
1.4 The references are a part of this practice to the extent specified in the text.
1.5 The values stated in metric (SI) units are to be regarded as the standard. The values given in parentheses are for information
purposes only.
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.
2. Referenced Documents
2.1 ASTM Standards:
E6 Terminology Relating to Methods of Mechanical Testing
3. Terminology
3.1 Definitions:
3.1.1 Refer to Terminology E6 for definitions of terms relating to stress and strain.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 Terms pertinent to this guide are described as follows:
3.2.2 capacitive strain gage—a strain gage whose response to strain is a change in electrical capacitance which is predictably
related to that strain.
3.2.3 conditioning circuit—a circuit or instrument subsystem that applies excitation to a strain gage, detects an electrical change
in the strain gage, and provides a means for converting this change to an output that is related to strain in the test article. The
conditioning circuit may include one or more of the following: bridge completion circuit, signal amplification, zero adjustment,
excitation adjustment, calibration, and gain (span) adjustment.
This practiceguide is 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.
Current edition approved April 1, 2009April 15, 2014. Published September 2009August 2014. Originally approved in 1989. Last previous edition approved in 20032009
as E1319 - 98 (2003).(2009). DOI: 10.1520/E1319-98R09.10.1520/E1319-98R14.
The boldface numbers in parentheses refer to the list of references at the end of this practice.guide.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E1319 − 98 (2014)
3.2.4 compensating gage—a gage element that is subject to the same environment as the active gage element, and which is
placed in the adjacent leg of a Wheatstone bridge to provide thermal, pressure, or other compensation in the strain gage system.
3.2.5 electrical simulation—a method of calibration whereby a known voltage is generated at the input of an amplifier,
equivalent to the voltage produced by a specific amount of strain.
3.2.6 free filament gage—a resistive strain gage made from a continuous wire or foil filament which is fixed to the test article
along the entire length of the gage, and which is supplied without a permanent matrix.
3.2.7 gage factor—the ratio between the unit change of strain gage resistance due to strain and the measurement. The gage factor
is dimensionless and is expressed as follows:
R 2 R L 2 L ΔR
o o
K 5 / 5 /ε (1)
R L R
o o o
where:
K = gage factor,
R = strain gage resistance at test strain,
R = strain gage resistance at zero or reference strain,
o
L = test structure length under the strain gage at test strain,
L = test structure length under the strain gage at zero or reference strain,
o
ΔR = change in strain gage resistance when strain is changed from zero (or reference strain) to test strain, and
ε =
L 2 L
o
mechanical strain
L
o
3.2.8 integral lead wire—a lead wire or portion of a lead wire that is furnished by a gage manufacturer as part of the gage
assembly.
3.2.9 linearity—the value measured as the maximum deviation between an actual instrument reading and the reading predicted
by a straight line drawn between upper and lower calibration points, usually expressed as a percent of the full scale of the sensor
range.
3.2.10 lead wire—a conductor used to connect a sensor to its instrumentation.
3.2.11 matrix—an electrically nonconductive layer of material used to support a strain gage grid. The two main functions of a
matrix are to act as an aid for bonding the strain gage to a structure and as an electrically insulating layer in cases where the
structure is electrically conductive.
3.2.12 resistive strain gage—a strain gage whose response to strain is a change in electrical resistance that is predictably related
to that strain.
3.2.13 shunt calibration—a method of calibration whereby a resistor or capacitor of known value is placed electrically in
parallel with another resistor or capacitor in a circuit, causing a calculable change in the total resistance or capacitance that is
predictably related to a specific amount of strain.
3.2.14 strain, linear—the unit elongation induced in a specimen either by a stress field (mechanical strain) or by a temperature
change (thermal expansion).
3.2.15 strain gage system—the sum total of all components used to obtain a strain measurement. May include a strain gage; a
means of attaching the strain gage to the test articles; lead wires; splices; lead-wire attachments; signal-conditioning and read-out
instrumentation; data-logging system; calibration and control system; environmental protection; or any combination of these and
other elements required for the tests.
3.2.16 static strain—a strain that is measured relative to a constant reference value, as opposed to dynamic strain, which is the
peak-to-peak value of a cyclic phenomenon, without reference to a constant zero or reference value (Fig. 1).
3.2.17 test article—an item to which a strain gage system is installed for the purpose of measuring strain in that item.
3.2.18 thermal compensation—the process by which the thermal output of a gage system is counteracted through the use of one
or more supplementary devices, such as a thermocouple or compensating gage. The counteraction may be integral to the gage
system or may be accomplished by data processing methods, or both.
3.2.19 thermal output—the reversible part of the temperature induced indicated strain of a strain gage installed on an
unrestrained test specimen when exposed to a change in temperature.
3.2.20 thermal output-unmounted—the reversible part of the temperature induced indicated strain of an unmounted strain gage
when exposed to a change in temperature.
4. Significance and Use
4.1 The use of this guide is voluntary and is intended for use as a procedures guide for selection and application of specific types
of strain gages for high-temperature installations. No attempt is made to restrict the type of strain gage types or concepts to be
E1319 − 98 (2014)
FIG. 1 Relationship Between Static and Dynamic Strain
chosen by the user. The provisions of this guide may be invoked in specifications and procedures by specifying those which shall
be considered mandatory for the purpose of the specific application. When so invoked, the user shall include in the work statement
a notation that provisions of this guide shown as recommendation shall be considered mandatory for the purposes of the
specification or procedure concerned, and shall include a statement of any exceptions to or modifications of the affected provisions
of this guide.
5. Gage Selection Criteria
5.1 The factors listed in this section must be considered when selecting a strain gage system for use in the temperature range
specified in 1.1. It is recognized that no gage may have all of the desired capabilities to meet all requirements of a particular test.
The risk of compromising certain test objectives must be evaluated, and some test objectives may have to be modified to match
the capabilities of the available gage selected. Guidelines for this evaluation are provided in Section 9.
5.2 Operating Temperature:
5.2.1 Isothermal Tests—Stability of the reference value with respect to time is essential when tests are to be made at constant
temperature. The stability of the candidate gage system at the specified temperature must be such that any shift that occurs in the
reference value is tolerable for the duration of the test.
5.2.2 Thermal Compensation and Transients—The adequacy of the thermal compensation must be considered when the
measurement of strain during a thermal transient is required. Thermal output is a function of temperature, thus its value at a
temperature depends not only on temperature, but on the temperature history followed in reaching that temperature. If significant
hysteresis in the thermal response is present, large errors or uncertainties can result. This is especially true when the calibration
procedure used to characterize the thermal output does not accurately reflect the temperature sequence to which the gages will be
exposed during testing. If the response time of the compensation is exceeded, the resulting uncertainty must be considered. The
ability of the gage system to withstand the transient without a detrimental shift of the reference value must be verified. This is true
whether or not strain is measured during the transient. Any gage factor change as a function of temperature change must also be
considered.
5.2.3 Precalibration:
5.2.3.1 Thermal output calibration on the structure is usually not possible and precalibration of gages on a similar material is
necessary. However, variations of up to 0.5 ppm/°F are possible within a material. Often, rolling direction will influence thermal
expansion coefficient.
5.2.3.2 Precalibration of resistive or capacitive strain gages is performed using a calibration fixture made from material similar
to the test article. The calibration fixture must be made to precisely fit the gage, especially if curvature is involved. Experience has
shown mating parts must be lapped together to provide uniform clamping pressure around the periphery of the gage weld area.
5.2.3.3 The calibration test should be repeated to ensure precise duplication of the calibration. Zero return should also repeat
exactly. If calibration data does not repeat; either the calibration set-up or the gages are faulty.
5.2.4 Post Test Calibration:
5.2.4.1 A more precise thermal output calibration can be achieved after the test by removing the test gage (cut it out of the
structure) and running a precision test on the test gage still attached to the test article material. The test coupon is relieved of all
induced stresses (thermal, mecahniacl, residual) and is free to expand freely with temperature. The integral gage lead wire should
be exposed to thermal gradients similar to those that occurred during the test program.
E1319 − 98 (2014)
5.3 Duration of Test—The ability of all parts of the gage system to function for the specified duration of test should be
demonstrated; if multiple tests are required on the same test article, the capability and effect of gage replacement must also be
established.
5.4 Strain Rate—The time response of the candidate gage system must be adequate to meet test requirements if rapid changes
of load are anticipated. It may be necessary to design the loading rate of the test to accommodate limitations of the strain
measurement system selected.
5.5 Environment—Some gages are limited to specific operating environments and therefore, the gage system selected must be
capable of withstanding the environment in which it will operate. Such limitations must be carefully considered when selecting
the gage system to be used. Factors such as pressure, vibration, radiation, magnetic fields, humidity, etc., must be considered. The
ambient and test environments of the elements of the strain gage system must be considered in the selection of lead wires,
connectors, instrumentation, and seals (when required).
5.6 Strain Range:
5.6.1 Total Strain Range—The maximum strain ranges of the candidate gage types must be defined and must be adequate for
the test. Mechanical strain attenuators, when permissible, may be added to extend the strain range of a given strain gage system,
subject to the limitation of 5.6.2.
5.6.2 Resolution—The ability of the candidate gage to measure small increments of strain within the total strain range should
be compared with the incremental strain measurement requirements of the test. When mechanical strain attenuators are used, the
resulting loss of resolution must be considered.
5.7 Strain
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.