Some standard content:
National Metrology Verification Regulation of the People's Republic of China JJG 762--2007
Extensometer
Extensometer
Issued on August 21, 2007
Implemented on February 21, 2008
General Administration of Quality Supervision, Inspection and Quarantine
JJG 762—2007
Verification Regulation
for Extensoneter
JJG 762—2007
Replaces JJG762—1992
This regulation was approved by the General Administration of Quality Supervision, Inspection and Quarantine on August 21, 2007, and came into effect on February 21, 2008.
Responsible unit: National Technical Committee on Force and Hardness Metrology Main drafting unit: General Iron and Steel Research Institute
Hubei Institute of Metrology and Testing Technology
Participating drafting unit: Changchun Testing Machine Research Institute of National University of Defense Technology
This regulation is entrusted to the National Technical Committee on Force and Hardness Metrology to be responsible for the interpretation of this regulation Main drafter:
JIG 762—2007
Wang Chunhua (China Iron and Steel Research Institute)
Wang Dachong (Hubei Institute of Metrology and Testing Technology)
Zheng Wenlong (National University of Defense Technology)
Participating drafters:
Wang Xuezhi (Changchun Testing Machine Research Institute)
Zhou Weisong (China Iron and Steel Research Institute)
Liang Xinbang (China Iron and Steel Research Institute)
Hu Xiang (Hubei Institute of Metrology and Testing Technology) Liu Jie (Hubei Institute of Metrology and Testing Technology)1
2Citations References·
Overview·
4 Gauge performance requirements·
5 General technical requirements,
5.1 Nameplate
5.2 Appearance and quality..
5.3 Display and output
6 Measuring instrument control
Verification conditions
6.2 Verification items and verification methods:
6.3 Processing of verification results
6.4 Verification cycle
Format of the inner page of the extensometer verification certificate
Appendix A
Appendix B Extensometer calibration record format
Appendix C Example of error band of extensometer
Appendix D Example of extensometer calibration
JJG 762—2007
(1)
：(1)
(1)
(3)
1 Scope
JJG 762—2007
Extensometer calibration procedure
This procedure applies to the initial calibration, subsequent calibration and in-use calibration of extensometers. 2 References
ONIHSE
This procedure references the following documents:
GB/T 228---2002
GB/T 1040.1
Metallic materials
Plastics
GB/T 7314-
"Metallic Materials
GB/T1212002/IS0953
JJF1096
System
302"Extensometer Standard Part
Room Temperature Tensile Test Method"
Part 1
(Uniaxial Test Method"
Extensometer Sample
H 02 Standard Practice for Verification and Classification When using this specification, attention should be paid to the use of industrial and commercial instruments or recording systems.
Valid version.
The testing machine measures the linear deformation of the specimen when applying a lateral force to the specimen.
Note: Electronic arc, such as resistance, the measured displacement display device can automatically record or display
mechanical extensometer, such as percentage
sensory extensometer
two types.
Working equipment
needs to be equipped with
rod type, optical type extensometer, by the banknote 3.2 When the extensometer is verified, the elastic
3.3 The verification of the extensometer is to obtain the final displacement of the system
of Extensometer
including the measuring, indicating
amplifier, computer or indicator
and its supporting whole measuring system.
Directly indicate the displacement and indicate the change in the given known length to compare the extensometer grade and determine the accuracy of the gauge to meet the requirements of GB/T228, GB/T1040, GB/T7314 and other tensile and compression test method standards for extensometers, and ensure the correctness of material test results. 4 Metrological performance requirements
4.1 The relative error of the gauge length of extensometers of each level shall comply with the provisions of Table 1. 4.2 The resolution of extensometers of each level shall comply with the provisions of Table 1. 4.3 The indication error and indication progress relative error of extensometers of each level shall comply with the provisions of Table 1. 1
Extensometer
Accuracy grade
Relative error of gauge length
JJG 762—2007
Extensometer measurement characteristics
Resolution
Indication error
Relative error
Absolute error
(ti-t)/μrn
Note: The relative error and absolute error ranges are shown in Appendix (. The infeed and return errors are calibrated according to customer needs. Infeed and return errors
Relative error
4.4 The calibration range of each level of extensometer should be determined according to the needs of the product or the measurement range required by the performance of the material being measured. The calibration can be carried out in multiple measuring ranges within the process. 5 General Technical Requirements
5.1 Nameplate
The nameplate of the extensometer and its supporting instruments shall indicate the instrument name, model, manufacturer name, product number and expiration date.
5.2 Appearance and Quality
The extensometer and its accessories shall not have obvious mechanical damage; the blade, shaft tip and other structures for setting the gauge length shall not have obvious wear; the indicating device and measuring mechanism shall not have defects that affect the measurement results. 5.3 Display and Output
The display of the electronic extensometer It should be clear, complete and stable, and the printed results or drawn curves should be consistent with the indicated values. 6 Measuring instrument control
Measuring instrument control includes: initial calibration, subsequent calibration and inspection during use. 6.1 Calibration conditions
6.1.1 Environmental conditions
The calibration temperature range should be 23℃±5℃. The temperature during calibration should be stable, and the temperature change should not exceed 2℃. The calibration process should not be filled with air convection that may affect the calibration results of the extensometer. For extensometers used for tests in the temperature range of 10℃35℃, if conditions permit, the test temperature can also be adjusted. Or close to the test temperature for calibration.
The extensometer and calibrator should be placed at the same room temperature for not less than 30 minutes, and then calibrate after the temperature is balanced.
6.1.2 Standard instruments for calibration
6.1.2.1 The extensometer calibrator should comply with the requirements of JJF1096-2002, and its allowable error should comply with the provisions of Table 2.
Corresponding extensometer accuracy
(rlt),/%
JJG.762-—2007
Table 2 Metering characteristics of calibrator
Metering characteristics of corresponding calibrator
Resolution
Relative error
Indication error
Absolute error
(i,-t)/μm
6.1.2.2 The maximum allowable error of the vernier caliper or tool microscope used to measure the gauge length of the extensometer shall not be greater than 1/3 of the maximum allowable error of the gauge length of the extensometer.
6.2 Verification items and verification methods
The first verification, subsequent verification and in-use inspection are the same. 6.2.1 Appearance inspection
The contents specified in Chapter 5 shall be inspected through observation and actual operation. 6.2.2 Installation requirements
The extensometer shall be installed on the calibrator in the position and direction used in normal ship tests, and errors caused by loss of balance or deformation of any part of the extensometer shall be avoided. The gauge length, magnification, mounting method, displacement direction, data reading and recording method and recording procedure of the inclination gauge used during calibration should be as consistent as possible with the usage status. 6.2.3 Verification of extensometer gauge length
For extensometers that can measure gauge length directly, the gauge length should be measured directly after the installation preparation is completed. When direct measurement is not possible, the extensometer can be installed on a soft metal specimen and the distance between the marks left by the extensometer blade or shaft tip on the specimen can be measured.
Each gauge length is measured 3 times, and the relative error of the minimum extensometer gauge length measured each time should meet the requirements of Table 1. The relative error of the extensometer gauge length is calculated according to formula (1). 4L
×100%
Where: α,—relative error of minimum extensometer gauge length, %; L——measured value of extensometer gauge length, mm; L. —Standard value of extensometer gauge length, mmu(1)
When the extensometer has multiple gauge lengths, each gauge length should be calibrated separately: For extensometers whose gauge length is determined by the specimen (for example, the gauge length is determined by the diameter or width of the specimen, and the gauge length of the specimen with lugs is determined by the distance between the center lines of the two lugs), the relative error of the gauge length of the tested specimen should be consistent with the allowable error of the corresponding level of the extensometer to be used.
6.2.4 Verification of resolution
JJG 762—2007
Absolute resolution is the minimum value that can be read from the indicating device of the extensometer. Relative resolution is the ratio of the minimum value that can be read from the instrument to the displacement indicated by the extensometer! ;. Daily inspection and calculation of the resolution of the extensometer, the result should meet the requirements of Table 1.
6.2.5 Verification of indication error
6.2.5.1 When the temperature has stabilized, use the calibrator to pre-apply at least two displacements corresponding to the calibration range of the extensometer to the extensometer before verification. After checking that it returns to zero normally, apply a small negative displacement to the extensometer and return to zero, and re-zero the extensometer.
6.2.3.2 Verification according to 4.4 The NIHSTHD verification shall be performed in three groups of measurements, each of which shall generally have no less than 10 measurement points (including the zero point). According to the selected verification range, use the calibrator to apply a given displacement to the reference point, and return to zero when the maximum displacement within the verification range is reached. After the first group of measurements is completed, the second group of measurements shall be performed continuously in the most accurate way. The detection points should be allocated according to your usage. For measuring the proportional extension strength and displacement values, it is generally not required to take the box in actual testing. The same distribution as the first group should be used on the non-proportional detector.
strength) of the extensometer. When the first test point
is used to measure the elastic modulus, the displacement value of the first test point should exceed 50% of the corresponding extension of the end point of the elastic straight line segment of the material being measured. For a given displacement, the extensometer indication is calculated using the temperature control formula (2):
where: 4—relative error of the indicated value, %
: 1—displacement indication m indicated by the calibration;
6.2.5.3 When necessary, the extensometer has the following measurements: for example, extension strength R. Or a specified residual extension R. In each set of measurements, the sense starts from the zero position R. For example: to determine the specified non-ratio by hysteresis). The calibration process is carried out according to 6.2.5.2. Then the displacement of the calibration range is determined, and then the return stroke is returned to the zero position point by point. The main group measurement is carried out in this way. The maximum value of the calibration range is 2% of the extensometer gauge length generally used. The indication of the extensometer is calculated by the relative H formula (3TO
A METROI
Where: u—relative error of extensometer indication in forward and reverse stroke, %; t—return displacement indication of the extensometer at the same test point, mm; t.—process displacement indication of the extensometer at the same test point, mm. 6.3 Treatment of calibration nests
6.3.1 Evaluate the level of the extensometer according to the calibration results of this regulation and issue a calibration certificate. The format of the inner page of the certificate is shown in Appendix A.
For extensometers that fail the calibration, a calibration result notice will be issued. And indicate the unqualified items. The format of the inner page is shown in JJG 762—2007
Appendix A.
When the extensometer is calibrated with multiple calibration ranges and multiple gauge lengths, the level of the extensometer shall be evaluated separately and a certificate shall be issued according to the corresponding level it meets.
6.3.2 Whenever the extensometer needs to be adjusted to meet the level requirements of its intended use, the word "adjusted" shall be noted on the calibration certificate. 6.4 Calibration cycle
The calibration cycle of the extensometer shall be determined according to the form of the extensometer, maintenance standards and frequency of use. Under normal circumstances, the calibration cycle of the extensometer is generally 12 months. Except for the flexure test lasting more than 18 months, the calibration cycle should not exceed hNMSH
18 months. In this case, the test
is calibrated.
METROLO
Appendix A
Accuracy level
Maximum deformation (mm)
Calibrator:
Measuring system:
Calibration items
Calibrator displacement
JJG 762—2007
Format of the inner page of the extensometer calibration certificate
Calibration results
Gauge length L, (tmm)
Calibration range (mm)
Gauge length error
Extensometer indication
Indication error
Displacement of the calibrator
Resolution
Calibration temperature:
Process error
Extensometer indication
Appendix B
Inspection unit||tt ||Calibrator:
Calibration item II
Calibration result
Calibrator indication
Calibration conclusion:
Calibrator:
Maximum deformation
JJG762—2007
Extensometer calibration record format
Extensometer calibration record
Manufacturer
Calibration range
Factory number
Measuring system:
Gauge length error
Extensometer Meter-indication/mm
Verifier:
Certificate No.
Verification temperature
Indication error
Factory level
Resolution
Humidity%
Advance and return error
Extensometer indication error
Relative error/%
Verification date:
Absolute error/μm
Appendix C
tr(in）
Applicable absolute value
±3.0μm)
JJG762—2007
Extensometer error band example
ONIHSI
The number expressed in
1-level extensometer is the position indicated by the extensometer,
Using H system relative error: 9 (=±1.0%)00
Calibrator
METROLOGY
1-level extensometer system error limit
Continuous displacement, um4 Confirmed calibration KH test 2NIHSTHD calibration requires three groups of measurements, each of which is generally not less than 10 measuring points (including zero point). According to the selected calibration range, the calibration device is used to apply a given displacement to the calibration point. When the maximum displacement of the calibration range is reached, it returns to zero. After the first group of measurements is completed, the second group of measurements is carried out continuously using the lowest calibration method. The test points should be allocated according to your use. For the displacement values used to measure the proportional extension strength, it is generally not specified in the actual test. The same distribution as the first group is used on the calibration device.
strength) of the extensometer. When the first test point
is used to measure the elastic modulus, the displacement value of the first test point should exceed 50% of the corresponding extension of the end point of the elastic straight line segment of the material being measured. For a given displacement, the extensometer indication is calculated using the temperature control formula (2):
where: 4—relative error of the indicated value, %
: 1—displacement indication m indicated by the calibration;
6.2.5.3 When necessary, the extensometer has the following measurements: for example, extension strength R. Or a specified residual extension R. In each set of measurements, the sense starts from the zero position R. For example: to determine the specified non-ratio by hysteresis). The calibration process is carried out according to 6.2.5.2. Then the displacement of the calibration range is determined, and then the return stroke is returned to the zero position point by point. The main group measurement is carried out in this way. The maximum value of the calibration range is 2% of the extensometer gauge length generally used. The indication of the extensometer is calculated by the relative H formula (3TO
A METROI
Where: u—relative error of extensometer indication in forward and reverse stroke, %; t—return displacement indication of the extensometer at the same test point, mm; t.—process displacement indication of the extensometer at the same test point, mm. 6.3 Treatment of calibration nests
6.3.1 Evaluate the level of the extensometer according to the calibration results of this regulation and issue a calibration certificate. The format of the inner page of the certificate is shown in Appendix A.
For extensometers that fail the calibration, a calibration result notice will be issued. And indicate the unqualified items. The format of the inner page is shown in JJG 762—2007
Appendix A.
When the extensometer is calibrated with multiple calibration ranges and multiple gauge lengths, the level of the extensometer shall be evaluated separately and a certificate shall be issued according to the corresponding level it meets.
6.3.2 Whenever the extensometer needs to be adjusted to meet the level requirements of its intended use, the word "adjusted" shall be noted on the calibration certificate. 6.4 Calibration cycle
The calibration cycle of the extensometer shall be determined according to the form of the extensometer, maintenance standards and frequency of use. Under normal circumstances, the calibration cycle of the extensometer is generally 12 months. Except for the flexure test lasting more than 18 months, the calibration cycle should not exceed hNMSH
18 months. In this case, the test
is calibrated.
METROLO
Appendix A
Accuracy level
Maximum deformation (mm)
Calibrator:
Measuring system:
Calibration items
Calibrator displacement
JJG 762—2007
Format of the inner page of the extensometer calibration certificate
Calibration results
Gauge length L, (tmm)
Calibration range (mm)
Gauge length error
Extensometer indication
Indication error
Displacement of the calibrator
Resolution
Calibration temperature:
Process error
Extensometer indication
Appendix B
Inspection unit||tt ||Calibrator:
Calibration item II
Calibration result
Calibrator indication
Calibration conclusion:
Calibrator:
Maximum deformation
JJG762—2007
Extensometer calibration record format
Extensometer calibration record
Manufacturer
Calibration range
Factory number
Measuring system:
Gauge length error
Extensometer Meter-indication/mm
Verifier:
Certificate No.
Verification temperature
Indication error
Factory level
Resolution
Humidity%
Advance and return error
Extensometer indication error
Relative error/%
Verification date:
Absolute error/μm
Appendix C
tr(in）
Applicable absolute value
±3.0μm)
JJG762—2007
Extensometer error band example
ONIHSI
The number expressed in
1-level extensometer is the position indicated by the extensometer,
Using H system relative error: 9 (=±1.0%)00
Calibrator
METROLOGY
1-level extensometer system error limit
Continuous displacement, um4 Confirmed calibration KH test 2NIHSTHD calibration requires three groups of measurements, each of which is generally not less than 10 measuring points (including zero point). According to the selected calibration range, the calibration device is used to apply a given displacement to the calibration point. When the maximum displacement of the calibration range is reached, it returns to zero. After the first group of measurements is completed, the second group of measurements is carried out continuously using the lowest calibration method. The test points should be allocated according to your use. For the displacement values used to measure the proportional extension strength, it is generally not specified in the actual test. The same distribution as the first group is used on the calibration device.
strength) of the extensometer. When the first test point
is used to measure the elastic modulus, the displacement value of the first test point should exceed 50% of the corresponding extension of the end point of the elastic straight line segment of the material being measured. For a given displacement, the extensometer indication is calculated using the temperature control formula (2):
where: 4—relative error of the indicated value, %
: 1—displacement indication m indicated by the calibration;
6.2.5.3 When necessary, the extensometer has the following measurements: for example, extension strength R. Or a specified residual extension R. In each set of measurements, the sense starts from the zero position R. For example: to determine the specified non-ratio by hysteresis). The calibration process is carried out according to 6.2.5.2. Then the displacement of the calibration range is determined, and then the return stroke is returned to the zero position point by point. The main group measurement is carried out in this way. The maximum value of the calibration range is 2% of the extensometer gauge length generally used. The indication of the extensometer is calculated by the relative H formula (3TO
A METROI
Where: u—relative error of extensometer indication in forward and reverse stroke, %; t—return displacement indication of the extensometer at the same test point, mm; t.—process displacement indication of the extensometer at the same test point, mm. 6.3 Treatment of calibration nests
6.3.1 Evaluate the level of the extensometer according to the calibration results of this regulation and issue a calibration certificate. The format of the inner page of the certificate is shown in Appendix A.
For extensometers that fail the calibration, a calibration result notice will be issued. And indicate the unqualified items. The format of the inner page is shown in JJG 762—2007
Appendix A.
When the extensometer is calibrated with multiple calibration ranges and multiple gauge lengths, the level of the extensometer shall be evaluated separately and a certificate shall be issued according to the corresponding level it meets.
6.3.2 Whenever the extensometer needs to be adjusted to meet the level requirements of its intended use, the word "adjusted" shall be noted on the calibration certificate. 6.4 Calibration cycle
The calibration cycle of the extensometer shall be determined according to the form of the extensometer, maintenance standards and frequency of use. Under normal circumstances, the calibration cycle of the extensometer is generally 12 months. Except for the flexure test lasting more than 18 months, the calibration cycle should not exceed hNMSH
18 months. In this case, the test
is calibrated.
METROLO
Appendix A
Accuracy level
Maximum deformation (mm)
Calibrator:
Measuring system:
Calibration items
Calibrator displacement
JJG 762—2007
Format of the inner page of the extensometer calibration certificate
Calibration results
Gauge length L, (tmm)
Calibration range (mm)
Gauge length error
Extensometer indication
Indication error
Displacement of the calibrator
Resolution
Calibration temperature:
Process error
Extensometer indication
Appendix B
Inspection unit||tt ||Calibrator:
Calibration item II
Calibration result
Calibrator indication
Calibration conclusion:
Calibrator:
Maximum deformation
JJG762—2007
Extensometer calibration record format
Extensometer calibration record
Manufacturer
Calibration range
Factory number
Measuring system:
Gauge length error
Extensometer Meter-indication/mm
Verifier:
Certificate No.
Verification temperature
Indication error
Factory level
Resolution
Humidity%
Advance and return error
Extensometer indication error
Relative error/%
Verification date:
Absolute error/μm
Appendix C
tr(in）
Applicable absolute value
±3.0μm)
JJG762—2007
Extensometer error band example
ONIHSI
The number expressed in
1-level extensometer is the position indicated by the extensometer,
Using H system relative error: 9 (=±1.0%)00
Calibrator
METROLOGY
1-level extensometer system error limit
Continuous displacement, um4 Calibration cycle
The calibration cycle of the extensometer depends on the form of the extensometer, maintenance standards and frequency of use. Under normal circumstances, the calibration cycle of the extensometer is generally 12 months. Except for the flexure test lasting more than 18 months, the calibration cycle should not exceed hNMSH
18 months. In this case, the test
is calibrated.
METROLO
Appendix A
Accuracy level
Maximum deformation (mm)
Calibrator:
Measuring system:
Calibration items
Calibrator displacement
JJG 762—2007
Format of the inner page of the extensometer calibration certificate
Calibration results
Gauge length L, (tmm)
Calibration range (mm)
Gauge length error
Extensometer indication
Indication error
Displacement of the calibrator
Resolution
Calibration temperature:
Process error
Extensometer indication
Appendix B
Inspection unit||tt ||Calibrator:
Calibration item II
Calibration result
Calibrator indication
Calibration conclusion:
Calibrator:
Maximum deformation
JJG762—2007
Extensometer calibration record format
Extensometer calibration record
Manufacturer
Calibration range
Factory numberbZxz.net
Measuring system:
Gauge length error
Extensometer Meter-indication/mm
Verifier:
Certificate No.
Verification temperature
Indication error
Factory level
Resolution
Humidity%
Advance and return error
Extensometer indication error
Relative error/%
Verification date:
Absolute error/μm
Appendix C
tr(in）
Applicable absolute value
±3.0μm)
JJG762—2007
Extensometer error band example
ONIHSI
The number expressed in
1-level extensometer is the position indicated by the extensometer,
Using H system relative error: 9 (=±1.0%)00
Calibrator
METROLOGY
1-level extensometer system error limit
Continuous displacement, um4 Calibration cycle
The calibration cycle of the extensometer depends on the form of the extensometer, maintenance standards and frequency of use. Under normal circumstances, the calibration cycle of the extensometer is generally 12 months. Except for the flexure test lasting more than 18 months, the calibration cycle should not exceed hNMSH
18 months. In this case, the test
is calibrated.
METROLO
Appendix A
Accuracy level
Maximum deformation (mm)
Calibrator:
Measuring system:
Calibration items
Calibrator displacement
JJG 762—2007
Format of the inner page of the extensometer calibration certificate
Calibration results
Gauge length L, (tmm)
Calibration range (mm)
Gauge length error
Extensometer indication
Indication error
Displacement of the calibrator
Resolution
Calibration temperature:
Process error
Extensometer indication
Appendix B
Inspection unit||tt ||Calibrator:
Calibration item II
Calibration result
Calibrator indication
Calibration conclusion:
Calibrator:
Maximum deformation
JJG762—2007
Extensometer calibration record format
Extensometer calibration record
Manufacturer
Calibration range
Factory number
Measuring system:
Gauge length error
Extensometer Meter-indication/mm
Verifier:
Certificate No.
Verification temperature
Indication error
Factory level
Resolution
Humidity%
Advance and return error
Extensometer indication error
Relative error/%
Verification date:
Absolute error/μm
Appendix C
tr(in）
Applicable absolute value
±3.0μm)
JJG762—2007
Extensometer error band example
ONIHSI
The number expressed in
1-level extensometer is the position indicated by the extensometer,
Using H system relative error: 9 (=±1.0%)00
Calibrator
METROLOGY
1-level extensometer system error limit
Continuous displacement, um
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