JJG 797-2013_English: PDF (JJG797-2013)
| Standard ID | Contents [version] | USD | STEP2 | [PDF] delivered in | Standard Title (Description) | Status | PDF |
| JJG 797-2013 | English | 180 |
Add to Cart
|
0--9 seconds. Auto-delivery
|
Verification Regulation of Calibration Instrument for Torque Wrenches
| Obsolete |
JJG 797-2013
|
Standards related to: JJG 797-2013
| Standard ID | JJG 797-2013 (JJG797-2013) | | Description (Translated English) | Verification Regulation of Calibration Instrument for Torque Wrenches | | Sector / Industry | Metrology & Measurement Industry Standard | | Classification of Chinese Standard | A53 | | Classification of International Standard | 17.100 | | Word Count Estimation | 18,139 | | Older Standard (superseded by this standard) | JJG 797-1992 | | Drafting Organization | China Institute of Metrology | | Administrative Organization | National Technical Committee of the force measured hardness values | | Regulation (derived from) | AQSIQ Announcement No. 63 of 2013 | | Issuing agency(ies) | State Administration of Quality Supervision, Inspection and Quarantine | | Summary | This standard applies to: electronic, mechanical and hydraulic torque wrench Calibrator (hereinafter referred to as torque meter) initial verification, testing and use of follow-up inspection. | JJG 797-2013
JJG
National Metrological Verification Regulations
of the People’s Republic of China
Calibration Instrument for Torque Wrenches
ISSUED ON. APRIL 27, 2013
IMPLEMENTED ON. OCTOBER 27, 2013
Issued by. General Administration of Quality Supervision, Inspection and
Quarantine
Verification Regulation of
Calibration Instrument for Torque Wrenches
Replacing JJG 797-1992
Administration organization. National Technical Committee of Force Value
and Hardness Measurement
Main Drafting organizations. National Institute of Metrology; and No.704
Institute of CSIC
Participating drafting organizations. Beijing Aerospace Measurement and
Testing Technology Research Institute; and Hubei Provincial Institute of
Measurement and Testing
National Technical Committee of Force Value and Hardness Measurement is
entrusted to be responsible for the explanation of this Regulation.
Main drafters of this Regulation.
Meng Feng (National Institute of Metrology)
Zhang Zhimin (National Institute of Metrology)
Li Tao (No.704 Institute of CSIC)
Participating drafters.
Mei Hongwei (Beijing Aerospace Institute of Measurement and
Testing Technology)
Lin Jing (No.704 Institute of CSIC)
Hu Xiang (Hubei Provincial Institute of Measurement and Testing)
Table of Contents
Introduction ... 5
1 Scope ... 6
2 Terminology ... 6
2.1 Standard torque wrench ... 6
2.2 Average arm length ... 6
2.3 Minimum arm length ... 6
3 General introduction ... 6
4 Measuring performance requirements ... 7
5 General technical requirements ... 8
5.1 Appearance ... 8
5.2 Technical performance ... 8
5.3 Use and replacement of indication instrument ... 8
5.4 Indication instrument ... 9
6 Measuring instrument control ... 10
6.1 Verification condition ... 10
6.2 Verification item and verification method ... 11
6.3 Process of verification result ... 17
6.4 Verification period ... 18
Appendix A Content format of verification certificate and verification
results ... 19
Appendix B Verification record of calibration instrument for torque
wrenches ... 20
Appendix C Verification steps ... 22
Appendix D Arm length for reference and literature ... 23
Introduction
This regulation was formulated according to Germany and Japan's current
verification method of calibration instrument for torque wrenches DKDR-3-8
and MIF 019, this Regulation replaces JJG 797-1992 "Calibration instrument
for torque wrenches." The main technical changes are that it adds verification
method of standard torque wrenches; VERIFY 0.3-grade and 0.5-grade
calibration instrument for torque wrenches, ADD indication value reproducibility
under same arm length and indication value reproducibility under different arm
length; ADD indication value reproducibility under different arm length for 1.0-
grade calibration instrument for torque wrenches, and it cancels verification
method for standard torque instrument.
Verification Regulation of
Calibration Instrument for Torque Wrenches
1 Scope
This Regulation applies to the initial verification, subsequent verification and
usage inspection of electronic, mechanical and hydraulic calibration instrument
for torque wrenches (hereinafter referred to as torque instrument).
2 Terminologies
2.1 Standard torque wrench
The torque wrench which has high accuracy and is used to conduct quantity-
value transfer for calibration instrument for torque wrenches.
2.2 Average arm length
The average length of torque wrench’s arm, within a certain range.
2.3 Minimum arm length
The minimum length of torque wrench’s arm, within a certain range.
3 General introduction
Torque instruments are the instruments used to verify (calibrate) various types
of manual torque wrenches. Torque instruments can be generally divided into
mechanical, hydraulic and electronic types (it usually uses strain torque sensor)
according to the working principle. It mainly includes two kinds according to the
structure. one is the calibration instrument for torque wrench with a loading
structure, another one is the calibration instrument for torque wrench without a
loading structure.
Mechanical and hydraulic torque instruments coaxially concatenate the wrench
of torque wrench to be verified AND the torsion elastomer of torque instrument.
When imposing torque directly or indirectly on the tail section of torque wrench,
specifications and user’s requirements.
5.3.2 Torque sensor and indication instrument shall support the use of each
other. Generally, they shall not be replaced randomly. If they need to be
replaced, the re-verification is needed.
5.4 Indication instrument
5.4.1 Analogue instrument
5.4.1.1 Scale and mark of each indication dial shall be clear, explicit and easy
to read. The zero and maximum value of each scale shall be explicitly marked.
5.4.1.2 It shall have reset mechanism to indicate zero and holding mechanism
of torque’s indication value.
5.4.1.3 The engraved lines on the dial shall be uniform, the width of pointer shall
be approximately equal to the width of engraved lines. The resolution shall be
determined according to the RATIO of the width of pointer AND the spacing
(scale spacing) between the centers of 2 adjacent engraved lines. The
recommended ratio is 1/2, 1/5 and 1/10. When the scale spacing is not less
than 1.25mm, 1/10 dial scale value may be estimated and read.
5.4.1.4 During the process of imposing torque, the pointer shall be smooth, and
have no abnormal phenomenon such as impact and stagnation. Active pointer
and passive pointer shall be coincide with the engraved lines of the dial, and be
parallel to the surface of dial.
5.4.1.5 The friction of active pointer shall be able to make passive pointer stay
in any position. When conducting verification with or without passive pointer, its
relative error of indication value shall not exceed the relative error of indication
value as specified by the corresponding accuracy grade. When the torque of
fixed-value type torque wrench is suddenly removed, the amount of change of
active pointer shall not be greater than 1/5 of the relative error of maximum
torque indication value of the corresponding accuracy grade.
5.4.2 Digital instrument
5.4.2.1 The connection between torque sensor and indication device shall be
reliable. And it shall have certain ability to resist to electromagnetic interference.
5.4.2.2 Each operation switch, button, knob and jack shall have words or
symbols marked on it, and the operation shall be flexible and reliable.
5.4.2.3 The indication of figures shall be clear and accurate. And it shall have
functions of continuation, peak holding and zero-adjustment.
5.4.2.4 The minimum figure increment shall be 1×10n, 2×10n or 5×10n, in which
n is a positive integer, a negative integer or zero. Each grade shall includes
zero and maximum value of its scale range. And it shall indicate the declining
symbols of less-than zero position (for example, displayed by the symbol "+" or
"-").
5.4.2.5 For those with function of digital signal output, the output data shall be
consistent with the indication value.
5.4.2.6 When torque instrument is without loading, if the indication value
change is not greater than 1 increment, then the resolution is 1 increment of the
last significant figure displayed; if the indication value change is greater than
one increment, then the resolution is the half of range of the indication value
change.
6 Measurement instrument control
Measurement instrument control includes. the initial verification, subsequent
verification and inspection when in use.
6.1 Verification condition
6.1.1 Environmental condition
According to the specification of torque instrument grade, verification of 0.3
grade and 0.5 grade shall be at room temperature of (20 + 5) ºC, verification of
1.0 grade and 2.0 grade shall be at room temperature of (20 + 10) ºC, and under
the condition of a relative humidity not greater ...
...
|