Some standard content:
National Metrology Verification Regulation of the People's Republic of China JJG41999
Steel Tape
SteelTape
Issued on September 6, 1999
Implemented on December 6, 1999
Issued by the State Administration of Quality and Technical Supervision
Verification Regulation
of Steel Tape
JJG4—1999
JJG4—1999
Replaces JJG4—1989
JJG398-1995
JJG399—1985
This regulation was approved by the State Administration of Quality and Technical Supervision on September 6, 1999, and came into effect on December 6, 1999.
Responsible unit: National Technical Committee for Geometry and Length Metrology Drafting unit: Tianjin Metrology Technology Research Institute This regulation entrusts the National Technical Committee for Geometry and Length Metrology to be responsible for the interpretation of this regulation. Main drafters:
Wang Kexi
JJG4—1999
(Tianjin Metrology Technology Research Institute)
(Tianjin Metrology Technology Research Institute)
(Tianjin Metrology Technology Research Institute)
2 Verification items and verification conditions
2. 1 Verification conditions
2.2 Verification items and verification tools for steel tape measures 3 Technical requirements and verification methods ·
3.1 Appearance and interaction between parts
3.2 Line width
3.3 Indication error
3.4 Indication error of the inspected steel tape measure
4 Processing of verification results and verification cycle
4.1 Processing of verification results
4.2 Verification cycle
JJG4—1999
JJG 41999
Verification procedures for steel tape measures
This procedure applies to the verification of newly manufactured and in-use ordinary steel tape measures, depth measuring steel tape measures and steel national rulers. Overview
Steel differential rulers are measuring tools for measuring length. According to their structure, they are generally divided into four types, as shown in Figure 1. (a) Roll-up tape measure
(6) Self-winding tape measure
1 foot ring: 2 foot belt: 3 foot box: 4 one car 1 foot period: 2 foot belt: 3 foot box: (e) Flexible tape measure
1 foot supply; 2 foot belt, 3 brake button: 4 foot box (a) Deep steel tape measure
1 foot belt: 2 foot energy: 3-shake blessing: 4-ruler frame
Steel tape measures can be divided into three types according to their uses:
a) Ordinary steel tape measures are used to measure the length of objects; b) Depth measuring steel tape measures are mainly used to measure the depth of liquids: JJG4-1999
c) Steel circumference rulers are mainly used to measure the diameter and circumference of objects. Steel circumference rulers are engraved with two scales, circumference ruler and diameter ruler, on the tape, which is convenient for measuring the circumference and diameter of cylindrical objects at the same time. The main structure of the tape measure is a whole steel belt with a certain elasticity, which is rolled into a metal (or plastic) material box or cabinet. The end of the ordinary steel tape measure is equipped with a ring or hook, and the brake-type lifting ruler is attached with a button device for winding the tape. The end of the depth measuring steel tape measure is equipped with a measuring tape, which can be connected to the tape in a fixed or hanging manner. The frame and the end of the bowl should be numbered the same. The tape can be divided into two types according to its mass: 0.7kg and 1.6kg. The nominal length of the steel tape measure: for steel tape measures below 10m, take an integer multiple of 0.5, and for steel tape measures above 10m, take an integer multiple of 5.
2 Verification items and verification conditions
2.1 Verification conditions
2.1.1 Verification temperature
When verifying Grade I steel tape, it should be (20±5)℃; when verifying Grade II steel tape, it should be (20±8)℃; the verification temperature of steel tape is (20±8)℃. 2.1.2 Tension during verification of steel tape
2.1.2.1 The tension during verification of ordinary steel tape and steel tape is 49N. 2.1.2.2 The tension during verification of depth-measuring steel tape is 9.8N for light tape and 15.7N for heavy tape according to the mass of its bowl.
2.1.2.3 The tension during verification of steel tape with nominal length less than 5m and curved tape is not specified. Note: The tension can also be determined according to the user's requirements, but it must be indicated on the calibration certificate, and the correction amount and measurement uncertainty must be given. The error of the tension should be less than 1N. 2.1.3 The time for the gauge to be tested to maintain a constant temperature at the specified temperature before calibration shall not be less than 4 hours. 2.2 Calibration items and calibration tools for steel tape measures The calibration items and calibration tools for steel tape measures are listed in Table 1 Table 1
Calibration items
Appearance and various parts
Interaction
Line width
Indication error
Main calibration tools
Calibration table, 5kg, 1kg, 1.6kg re-paving
Reading microscope with a graduation value of 0.01mm
Standard steel tape measure, zero calibration part, calibration table, reading microscope with a graduation value of 0.01mm, heavy chain
Note: "+" in the table means that calibration is required, and "" means that calibration is not required. 2
Verification category
New
In use
3 Technical requirements and verification methods
3.1 Appearance and interaction of various parts
3.1.1 Requirements
JJG4—1999
3.1.1.1 The pulling out and winding of the steel tape measure should be light and flexible without obstruction, and each functional device should be able to effectively control the winding of the tape.
3.1.1.2 Lay the tape flat on the verification table and apply the specified tension. The tape surface should not be uneven or twisted. The two edges of the tape must be smooth, without sharp edges and burrs, and the tape width should be uniform. The hook should be kept at a right angle and there should be no visible deviation.
3.1.1.3 The surface of the tape should have an anti-corrosion layer, and it should be firm, flat and smooth, with uniform color, no obvious bubbles, peeling and wrinkles, no rust, spots, scratches and other defects. 3.1.1.4 All the scale lines of the tape must be uniform, clear and vertical to the edge of the tape, without double lines or missing lines. Individual lines are allowed to have broken lines not greater than the width of the line: 3.1.1.5 The zero value line of the ordinary steel tape and the steel circumference ruler is generally 100mm away from the pull ring, and the whole point line is 250mm away from the opening of the ruler box. The zero position of the depth measuring steel tape is at the end of the ruler bowl, and the end point line is 250mm away from the opening of the ruler box. 3.1.1.6 The scale values of ordinary steel tape are 1tmm, 5mm, and 10mm. Their line lengths should be clearly different. The scale values of the depth measuring steel tape and the copper circumference ruler are Imme. The same type of lines should be of equal length. 3.1.1.7 In each decimeter (dm), the centimeter (em) graduation line should be marked with a value in centimeters (cm) as the counting unit. For steel coils with a total length of less than 5m, the decimeter (dm) and meter (m) graduation lines should be counted from the zero point line and marked with a value in centimeters (cm) as the counting unit. For steel tapes with a total length of more than 5m, the decimeter (dm) graduation lines should be marked with a value in centimeters (cm) as the counting unit in each meter (m), and the meter graduation lines should be counted from the required position line, and the value in meters (m) should be marked for each meter (n); after 10m, the unit m may not be marked. 3.1.1.8 The various connecting parts of the steel tape should be firm and reliable, and not prone to tensile deformation. 3.1.1.9 The straightness of ordinary steel tapes with arc-shaped tape bearing surfaces should be: when the tape is extended horizontally to the length specified in Table 2, it cannot be folded down. Table 2
Tape width
Tape extension length
3.1.1.10 When the steel tape forms a circle with a diameter of 30mm at any position, the tape shall not be folded and shall recover naturally after being released. Plastic deformation is not allowed and cracks are not allowed on the coating. The tape or the box of the steel tape measure shall be marked with the full length, model, manufacturer name (or trademark) MC3.11.11
JJG4--1999
marked with factory number and year of production. Numbers and words must be clear and neat. The surface of the box (or frame) shall be smooth and free of cracks, rust and incompleteness. The appearance and interaction of the various parts of the newly made steel tape measure shall meet the above requirements. The steel tape measure in use shall not have appearance defects that affect the accuracy.
3.1.2 Verification method
Test and visual observation.
3.2 Line width
3.2.1 Requirements
Line width and error are shown in Table 3
Line width
Graduation value
0.15~0.30
3.2.2 Verification method
10% of the graduation value
Width error
Carrying width
Line perception
Visual observation, if there is any doubt, can be verified with a reading microscope with a graduation value of 0.01mm: 3.3 Indication error
3.3.1 Requirements
3.3.1.1 Zero value error
The zero value error of the depth measuring steel tape is the error from the end of the ruler bowl to the 500mm line, and the allowable error is ±0.5mmc
3.3.1.2 The allowable error between any two lines is 4. Under the standard conditions of verification, the different accuracy levels of the steel tape are calculated by the following formula:
Grade I: 4±(0.1+0.1/mmwwW.bzxz.Net
Grade A= (0.3+0.2L)m
where, the length is in meters. When the length is not an integer multiple, take the nearest larger integer "meter" number
For ordinary steel differential tapes with pull rings or hooks (i.e. the zero point is on the end face of the pull ring or hook), the absolute value of the allowable error of the length from one end face of the tape to any line interval can be increased: 0.1mm for Class 1 tapes: 0.2mm for Class II tapes Note: The error of the depth measuring steel tape refers to the allowable error of any two lines after the 500mm line. 3.3.1.3 The allowable error of millimeter division and meter division is shown in Table 4. Graduation value
JJG4-1999
Allowable error
Class I steel tapes in use can be downgraded when they are found to not meet the requirements of Class 1 after verification. 3.3. 2 Verification method
3.3.2.1 Zero error verification method
Put a common steel tape measure with a ruler or pull ring on the end of the ruler flat on the copper tape measure verification table, add the specified tension, and compare it with the first-level standard steel tape measure that has passed the verification. The ruler hook (or pull ring) indicating the zero position is aligned with the zero value line of the standard steel tape measure, and the error value is read at 100mm. The zero value error of the depth measuring steel tape measure is verified by a zero position calibrator as shown in Figure 2. 2
1-Baffle; 2-V-shaped support; 3-Target: 4-Ruler tape: 5-Wheel: 6-Ruler white First, place the ruler of the depth measuring steel tape measure to be tested on the V-shaped support of the zero position calibrator, so that its front end face is close to the zero position baffle of the zero position calibrator, and the ruler tape axis is parallel to the calibrator table. At this time, Read the zero value error at the 5
marked with 500mm lines on the table. JJG4—1999
3.3.2.2 Verification method for indication error of any section of steel tape measure Use a qualified standard steel tape measure of the working grade on the steel tape measure verification table to compare and measure with the inspected ruler (the friction between the steel tape measure verification table and the inspected ruler should be ≤4N). First, use a clamping device to fasten the standard steel tape measure and the inspected steel tape measure on the verification table, and add the corresponding square to the other end of the standard ruler and the inspected ruler respectively according to the regulations. Adjust the zero adjustment mechanism on the verification table to align the zero value lines of the broken inspection with the zero value lines of the standard ruler (the auxiliary steel tape measure is aligned with the zero value lines of the standard steel tape measure with the lines at 500mm: read the errors of each section and the total length continuously for each meter section. For steel tape measures with a total length of less than 3m, the inspected sections should be no less than 3 sections. The indication error between the two sections is selected in meters for verification. The indication error shall not exceed the allowable error requirement of the corresponding section. When the length of the full length of the ruler to be inspected is verified by hand, the division method can be used for verification. The error of the full length is the error of each section. The indication error of the circumference ruler should be verified first, and then the indication error of the diameter ruler should be verified. At this time, the reading must be aimed at the reading with a reading microscope with a graduation value of 0.01mm. When there is doubt about the indication error of millimeters and centimeters, it is verified with a reading microscope with a graduation value of 0.01mm. The verification of the indication error of
can also be verified by other methods with a measurement uncertainty of 1/4 to 1/10 of the allowable error of the indication of the inspected ruler.
3.4 The indication error of the inspected steel tape measure
should be the algebraic sum of the reading value at the inspected point and the correction value of the standard steel tape measure. The indication error of the depth measuring steel tape measure is the algebraic sum of its zero value error and the indication error of the tape after 500mm. 4 Processing of verification results and verification cycle
4.1 Processing of verification results
Steel tape measures that have been verified to meet the requirements of this regulation should be stamped with the corresponding grade and issued a verification certificate. The correction value of the depth measuring steel tape measure will be given in the verification certificate. Those who fail to meet the requirements will be issued a verification result notice. 4.2 Verification cycle
The verification cycle of steel tape measures in use is generally half a year, and the longest shall not exceed 1 year. People's Republic of China
National Metrology Verification Regulations
Steel Tape
JJG4—1999
Published by the State Administration of Quality and Technical Supervision
Published by China Metrology Press
No. 2, West Hepingli Street, Beijing
Postal Code 100013
Tel (010) 64275360
E-mallJlfche 2a1.net.cn
Beijing Dixin Printing Co., Ltd. Guangdian Printing Co., Ltd.
Published by Beijing Publishing House of Xinhua Bookstore
All rights reserved. Reprint without permission
880-mm×1230mm6-size
1st edition in November 1999
Printing sheet 0.75 Words 9,000 Words
3rd printing in April 2003
Printing number 4201-6200
Online book number 155026-1077
Price: 12.00 yuan0.1mm reading microscope aiming reading. When there is doubt about the indication error of millimeter and centimeter scale, it is verified with a reading microscope with a graduation value of 0.01mm. The indication error can also be verified by other methods with a measurement uncertainty of 1/4 to 1/10 of the allowable error of the indication of the inspected ruler.
3.4 The indication error of the inspected steel lifting ruler
should be the algebraic sum of the reading value of the inspected point and the correction value of the standard steel tape measure. The indication error of the depth measuring steel coupon ruler is the algebraic sum of its zero value error and the indication error of the ruler tape after 500mm. 4 Processing of verification results and verification cycle
4.1 Processing of verification results
Steel tape measures that have been verified to meet the provisions of this regulation should be stamped with the corresponding grade and issued a verification certificate. The correction value of the depth measuring steel tape measure is given in the verification certificate. Those who fail to meet the requirements will be issued a verification result notice. 4.2 Verification cycle
The verification cycle of steel tapes in use is generally half a year, and the longest shall not exceed 1 year. People's Republic of China
National Metrology Verification Regulations
Steel Tape
JJG4—1999
Published by the State Administration of Quality and Technical Supervision
Published by China Metrology Press
No. 2, West Hepingli Street, Beijing
Postal code 100013
Tel (010) 64275360
E-mallJlfche 2a1.net.cn
Beijing Dixin Printing Co., Ltd. Guangdian Printing Co., Ltd.
Published by Beijing Publishing House of Xinhua Bookstore
All rights reserved. Reprint without permission
880-mm×1230mm6-size
1st edition in November 1999
Printing sheet 0.75 Words 9,000 Words
3rd printing in April 2003
Printing number 4201-6200
Online book number 155026-1077
Price: 12.00 yuan0.1mm reading microscope aiming reading. When there is doubt about the indication error of millimeter and centimeter scale, it is verified with a reading microscope with a graduation value of 0.01mm. The indication error can also be verified by other methods with a measurement uncertainty of 1/4 to 1/10 of the allowable error of the indication of the inspected ruler.
3.4 The indication error of the inspected steel lifting ruler
should be the algebraic sum of the reading value of the inspected point and the correction value of the standard steel tape measure. The indication error of the depth measuring steel coupon ruler is the algebraic sum of its zero value error and the indication error of the ruler tape after 500mm. 4 Processing of verification results and verification cycle
4.1 Processing of verification results
Steel tape measures that have been verified to meet the provisions of this regulation should be stamped with the corresponding grade and issued a verification certificate. The correction value of the depth measuring steel tape measure is given in the verification certificate. Those who fail to meet the requirements will be issued a verification result notice. 4.2 Verification cycle
The verification cycle of steel tapes in use is generally half a year, and the longest shall not exceed 1 year. People's Republic of China
National Metrology Verification Regulations
Steel Tape
JJG4—1999
Published by the State Administration of Quality and Technical Supervision
Published by China Metrology Press
No. 2, West Hepingli Street, Beijing
Postal code 100013
Tel (010) 64275360
E-mallJlfche 2a1.net.cn
Beijing Dixin Printing Co., Ltd. Guangdian Printing Co., Ltd.
Published by Beijing Publishing House of Xinhua Bookstore
All rights reserved. Reprint without permission
880-mm×1230mm6-size
1st edition in November 1999
Printing sheet 0.75 Words 9,000 Words
3rd printing in April 2003
Printing number 4201-6200
Online book number 155026-1077
Price: 12.00 yuan
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