JJG 26-2001 Lever Micrometer Lever Caliper JJG26-2001 Standard download decompression password: www.bzxz.net
This standard applies to the initial verification, subsequent verification and in-use inspection of lever micrometers with a graduation value of 0.001mm, 0.002mm and a measuring range upper limit of 100mm and lever calipers with a graduation value of 0.001mm, 0.002mm, 0.005mm and a measuring range upper limit of 200mm. The main metrological performance tests for finalization and prototype testing can be carried out in accordance with this regulation.

National Metrology Verification Regulation of the People's Republic of China JJG26—2001
Micrometers with Dial Comparator and Indicating Snap Gauge
Promulgated on November 30, 2001
Implementation on March 1, 2002
Promulgated by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China JJG26—2001
Verification Regulation of theMicrometers with Dial Comparator and Indicating Snap Gauge JJG26—2001
Replaces JJG26—1986
JJG27-—1980
This regulation was approved by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China on November 30, 2001, and came into effect on March 1, 2002.
Responsible unit:
Main drafting unit:
Participating drafting unit:
National Technical Committee for Metrology of Geometric Engineering Parameters Heilongjiang Metrology Verification and Testing Institute
Harbin Metrology Verification and Testing Institute
Guangxi Metrology and Testing Institute
This regulation is entrusted to the National Technical Committee for Metrology of Geometric Engineering Parameters to be responsible for the interpretation of this regulation. Main drafters:
Zhang Liping
Sun Defen
Liang Yuhong
Participating drafters:
Quan Yizhi
JJG26—2001
(Heilongjiang Metrology Verification and Testing Institute)||tt ||(Harbin Metrology Verification and Testing Institute)
(Heilongjiang Metrology Verification and Testing Institute)
(Guangxi Metrology and Testing Institute)
1 Scope·
2 References·
3 Overview·
4 Metrology performance requirements·
JJG26—2001
4.1 Surface roughness of measuring surface of lever scale and calibration rod·4.2 Measuring force and force variation
Axial movement of micrometer screw…Flatness of measuring surface
Parallelism of two measuring surfaces of lever scale
Indication error and indication variation of indicator
Produced when locking adjustable measuring rod 4.8
Indication error of lever micrometer
Working dimension deviation and parallelism of calibration rod4.10
Azimuth error of indicator
5 General technical requirements·
5.1 Appearance and surface quality
Interaction between various parts
Relative position of pointer and dial
5.4 Graduation width, difference in graduation width and pointer width·….5.5 Distance from the upper edge of the cone surface of the differential cylinder of lever micrometer to the longitudinal graduation surface of the fixed sleeve5.6 Relative position of the end face of the cone surface of the differential cylinder and the horizontal graduation of the fixed sleeve6 Control of measuring instruments
6.1 Verification items and main calibrators Tools:
Verification conditions
Verification methods
Processing of verification results
6.5 Verification cycle·
（3）
·（5)
1 Scope
JJG26-—2001
Verification procedures for lever micrometers and lever calipers This procedure is applicable to the initial verification, subsequent verification and in-service inspection of lever micrometers with a graduation value of 0.001mm, 0.002mm and a measuring range upper limit of 100mm and lever calipers with a graduation value of 0.001mm, 0.002mm, 0.005mm and a measuring range upper limit of 200mm (hereinafter collectively referred to as lever gauges). The main metrological performance tests for finalization and prototype testing can be carried out in accordance with this procedure.
2 References
This specification refers to the following documents:
GB8061-1987 "Lever Micrometer"
JB3237--1991 "Lever Caliper"
JJF1001--1998 "General Metrology Terms and Definitions" JJF1059-1999 "Evaluation and Expression of Uncertainty in Measurement" When using this specification, attention should be paid to using the current valid versions of the above referenced documents. 3 Overview
The lever ruler is a measuring instrument that uses the transmission of the lever and gear mechanism in the ruler frame to convert the linear displacement of the movable measuring anvil into the angular displacement of the pointer. It is mainly used to measure the external dimensions of precision parts. The schematic diagrams of the lever micrometer and lever caliper are shown in Figures 1 and 2 respectively, and the schematic diagram of the lever transmission mechanism is shown in Figure 3. 4 Metrological performance requirements
4.1 The surface roughness of the measuring surface of the lever scale and the calibration rod The surface roughness of the measuring base surface of the lever scale and the calibration rod R. should not exceed 0.05um. 4.2 Measuring force and force change
The measuring force and force change of the lever scale are shown in Table 1.
Table 1 Measuring force and force change
Measuring range/mm
Measuring force/N
Measuring force change/N
4.3 Axial movement of the micrometer screw of the lever micrometer 50
The axial movement of the micrometer screw of the lever micrometer should not exceed 1/2 of the scale of the dial for the new one. It should not exceed 1 scale of the dial during use and after repair. 1
JJG26—2001
Figure 1 Lever micrometer
1—Rise stand; 2—Movable measuring brick: 3—Micrometer screw; 4—Locking device; 5—Fixed sleeve; 6—Differential cylinder; 7—Push button: 8—Insulation device: 9—Indicator: 10—Zero adjustment mechanism: 11—Tolerance indicator 10
Figure 2 Lever calliper gauge
1—Brake handle; 2—Adjusting nut: 3—Rise stand, 4—Adjustable measuring rod; 5—Movable measuring anvil; 6—Indicator; 7—Push button; 8—Tolerance indicator: 9—Zero adjustment mechanism; 10—Location column: 11—Insulation device 4.4 Flatness of measuring surface
The flatness of measuring surface is shown in Table 2.
During calibration, the diameter of the measuring surface is 6.5mm, 8mm, and the range of 0.2mm from the edge is not counted, and the range of 0.5mm from the edge is not counted for the measuring diameter above 8mm. 2
4.5 Parallelism of the two measuring surfaces of the lever ruler
JJG26-2001
Figure 3 Lever transmission mechanism
When the measuring rod is locked, the parallelism of the two measuring surfaces of the lever ruler is shown in Table 2. Table 2 Flatness and parallelism of measuring surfaces
Parallelism of the two measuring surfaces of the lever ruler/μm
Measuring range/mm
(0，,25)
[25，50
[50，75
[75，100
[100，125]
[125，150
[150，175]
[175，200]
Flatness of measuring surface of lever caliper
/μm
Flatness of measuring surface of lever and scale
/μm
4.6 Indication error and indication change of indicator The indication error and indication change of the indicator are shown in Table 3. Indicator
Division
Table 3 Indicator error and indication change
Division
Indicator error
Within ±10 divisions
4.7 Indicator change when the adjustable measuring rod is lockedOutside ±10 divisions
Parallel flat crystal
Gauge block calibration
Indicator change
JJG26—2001
Indicator change when the adjustable measuring rod is locked, the lever should not exceed 0.5um for the scale, and the lever caliper should not exceed 1 division.
4.8 Indicator error of lever micrometer
See Table 4 for the indicator error of lever micrometer.
Table 4 Indication error of lever micrometer
Indication error um
Measuring range/mm
(0,25)
[25,50]
[50,75]
[75,100]
Newly manufactured
In use
4.9 Working dimension deviation and parallelism graduation value of calibration rod
Newly manufactured
In use
The working dimension deviation of calibration rod shall not exceed ±0.5μm, and the parallelism of the two measuring surfaces shall not exceed 0.5μm. During calibration, the range of 0.2mm from the edge of the measuring surface diameter shall not be counted. 4.10 Indicator position error
The indication value of the indicator changes when the lever scale is in the horizontal and vertical positions: the graduation value is 0.001mm and does not exceed 0.3μm; the graduation value is 0.002mm and does not exceed 0.5μm; the graduation value is 0.005mm and does not exceed 1μm. 5 General technical requirements
5.1 Appearance and surface quality
The working surfaces of the lever scale should be free of rust, bruises, spots and scratches. Other surfaces should be free of rust, paint peeling, coating shedding, burrs and other defects that affect performance. The scale lines and numbers on the dial and micrometer head should be clear, straight and even, without broken lines and discoloration. The surface should be transparent and clean, without bubbles, ripples, scratches and other defects that affect the reading quality. The lever scale must be marked with the manufacturer's name (or trademark), factory number, graduation value, measurement range and logo.
The lever scale in use and after repair should not have appearance defects that affect performance. 5.2 Interaction of various parts
5.2.1 The interaction of various moving parts should be flexible and reliable. 5.2.2 The rotation of the differential cylinder and the adjusting nut and the movement of the micrometer screw and the adjustable measuring rod should be smooth and without sticking. The micrometer screw should not have radial swing that can be felt by hand. 5.2.3 The pointer of the indicator should move smoothly and flexibly without jumping or jamming. In the free state, the pointer should be located outside the negative scale; when the button is pressed, the pointer should be able to move to the outside of the positive scale. 5.2.4 The movement of the movable anvil should exceed 0.5mm. A
5.2.5 The locking device should be effective. JJG26-—2001
5.2.6 The adjustment range of the zero adjustment device should be no less than ±5 divisions. The zero position is not allowed to change under working conditions. 5.2.7 The tolerance band indicator should be easy to adjust and can be adjusted to any scale position on the dial. It should not change under working conditions.
5.3 The relative position of the pointer and the dial
The direction of the pointer end and the dial scale should be consistent, without visible tilt. The distance from the upper surface of the pointer end to the dial surface should not exceed 0.5mm, and the pointer should cover 30%~80% of the length of the short scale on the dial. 5.4 Graduation width, difference in graduation width and pointer width 5.4.1 The width of the vertical graduations on the fixed sleeve and the differential cylinder of the lever micrometer is 0.15mm~0.20mm; the difference in graduation width should not exceed 0.03mm.
5.4.2 The width of the dial graduation is 0.1mm~0.2mm, and the difference in graduation width should not exceed 0.05mm 5.4.3 The width of the pointer end is 0.1mm~0.2mm, and the difference between the width of the pointer end and the width of the dial graduation should not exceed 0.05mm.
5.5 The distance from the upper edge of the cone edge of the differential cylinder of the lever micrometer to the vertical graduation surface of the fixed sleeve The distance from the upper edge of the cone edge of the differential cylinder of the lever micrometer to the vertical graduation surface of the fixed sleeve is α, and its value should not exceed 0.4mm (see Figure 4).
Figure 4 Distance from the upper edge of the differential cone to the vertical scale line of the fixed sleeve 5.6 Relative position of the end face of the differential cone and the horizontal scale line of the fixed sleeve When the zero scale line of the differential cone is aligned with the vertical scale line of the fixed sleeve, the end face of the differential cone and the right edge of the horizontal scale line of the fixed sleeve should be tangent. The pressure line is allowed to be no more than 0.05mm, and the offline pressure line is no more than 0.10mm (see Figure 5). (a) Offline 0.03mm
(b) Pressure line 0.03mm
Figure 5 Relative position of the end face of the differential cone and the horizontal scale line of the fixed sleeve 5
6 Control of measuring instruments
JJG26—2001
Control of measuring instruments includes initial verification, subsequent verification and in-use inspection. Verification items and main verification instruments
Verification items and main verification instruments are shown in Table 5. Table 5 Verification items and main verification instruments Verification items Interaction between various parts Relative position of pointer and dial Width of scale lines, width difference and pointer width Distance from the upper edge of the differential cone to the vertical scale line of the fixed sleeve Relative distance between the end face of the differential cone and the horizontal scale line of the fixed sleeve |tt||Position
Surface roughness of measuring surface of lever scale and calibration rod
Measurement force and change of measurement force
Axial movement of micrometer screw
Flatness of measuring surface
Parallelism of two measuring surfaces
Indication error of indicator and
Indication changewww.bzxz.net
Indication caused by locking measuring rod||tt ||Value change
Indication error of lever micrometer
Working size of calibration rod
DeviationParallelism of two measuring surfaces
Azimuth error of indicator
Main calibration instruments
Secondary feeler gauge
Tool microscope
Tool microscope
Tool microscope
Surface roughness comparison sample
Division value does not exceed| |tt||O.2N dynamometer
dynamometer
secondary flat crystal
parallel flat crystal or
fourth-level block
third-level block
fourth-level block
fifth-level block
fourth-level block
horizontal length measuring instrument, length measuring machine
and third-level block
Note: "+" in the table means that it should be calibrated, and "-" means that it can be not calibrated. 6
calibration category
in use
6.2 calibration conditions
JJG26—2001
calibration room temperature is (20±5)℃. Before calibration, the time for the lever scale and calibration equipment to balance the temperature in the calibration room should be no less than 2h.
6.3 Verification method
6.3.1 Appearance
Visual observation.
6.3.2 Interaction of various parts
Visual observation and manual test.
6.3.3 Relative position of pointer and dial
Visual observation. For the verification of the distance from the upper surface of the pointer end to the dial scale surface, observe with a 5x objective lens on a tool microscope when necessary. When the upper surface of the pointer and the dial are clearly imaged in the eyepiece field of view, record the two readings of the micro-motion lifting reading device (or additional dial indicator) of the microscope tube respectively, and the difference between the two numbers is taken as the verification result. 6.3.4 Scale width, scale width difference and pointer width The vertical scale width of the fixed sleeve of the lever micrometer, the scale width of the differential barrel, the scale width of the dial, and the width of the pointer end are measured on a tool microscope. Take at least 3 scale lines on the fixed sleeve, differential cylinder and dial, and record the width of each scale line. The difference between the maximum and minimum scale line widths of the fixed sleeve, the difference between the maximum and minimum scale line widths of the differential cylinder, and the difference between the maximum and minimum scale line widths of the dial is the scale line width difference. The maximum value of the difference between the width of the pointer end and the scale line width of the dial is the width difference. 6.3.5 The distance from the upper edge of the cone edge of the differential cylinder to the vertical scale line of the fixed sleeve is measured on a tool microscope using the above method (relative position of the pointer and the dial). A secondary feeler gauge with a thickness of 0.4mm can also be used for comparison. The calibration is performed every 90° rotation within one circle of the differential cylinder. 6.3.6 The relative position of the end face of the cone surface of the differential cylinder and the horizontal scale line of the fixed sleeve When the lower limit of measurement is adjusted correctly, rotate the differential cylinder so that its zero scale line is aligned with the vertical scale line of the fixed sleeve, and observe whether the end face of the cone surface of the differential cylinder is tangent to the right edge of the horizontal scale line of the fixed sleeve. If they are not tangent, rotate the differential cylinder to make them tangent, and read the offset of its zero scale line to the vertical scale line of the fixed sleeve according to the differential cylinder. This offset is the value of offline or line pressing.
6.3.7 The surface roughness of the measuring surface of the lever scale and the measuring surface of the calibration rod is compared with the R.0.1~0.012um grinding surface roughness comparison template. 6.3.8 Force measurement and force change
Use a dynamometer with a graduation value not exceeding 0.2N, place the axis of the movable anvil in the vertical direction and make the measuring brick contact the spherical probe of the dynamometer. When the pointer is at the two extreme positions of the dial, read two values ​​on the dynamometer, which is the measured force, and the difference between the two numbers is the force change.
6.3.9 Axial movement of the micrometer screw of the lever micrometer Adjust the measuring rod so that the measuring surface (use an extension rod if the measuring lower limit is above 25mm, see Figure 6) contacts the measuring surface of the anvil, and adjust the pointer of the indicator to near zero, and apply a pressure of 10N along the axial direction at the tail end of the micrometer screw; the change of the pointer is the calibration result. 6.3.10 Flatness of the measuring surface of the lever scale
The flatness of the two measuring surfaces is calibrated by the technical light wave interference method using a 2-level flat crystal. During the calibration, the flat crystal is ground with the measured surface and the number of interference bands is read. The flatness is calculated using the following formula. 4=0.3n
Where:——Flatness, μm;
Number of interference bands.
6.3.11 Parallelism of the two measuring surfaces of the lever micrometer The parallelism of the two measuring surfaces can be verified by using parallel crystals or gauge blocks. (1)
When using parallel crystals for verification, place a group of four parallel crystals of appropriate size between the two measuring surfaces of the lever micrometer in sequence, move the measuring rod so that the two measuring surfaces are in contact with the parallel crystals, and gently rotate the crystals to minimize the number of interference fringes appearing on the two working surfaces. Lock the measuring rod, record the sum of the number of interference fringes appearing on the two measuring surfaces, and take the value with the largest number of interference fringes among the four parallel crystals as the verified result. When verifying the lever caliper, one parallel crystal can be used to measure the parallelism of the two measuring surfaces in the same way. When using gauge blocks for verification, select gauge blocks with a size between the upper and lower limits of the lever micrometer, and four gauge blocks with a size interval of 1/4 of the pitch of the measuring rod. First, place the gauge block on the measuring surface at position 1 (see Figure 7), align the zero position and lock the measuring rod, and use the gauge block to test the indications at the 2nd, 3rd, and 4th positions on the measuring surface in the same position, read the readings on the indicator and find the difference between the maximum and minimum readings. The same method is used to obtain the calibration results of the other three gauge blocks, and the maximum value of the four differences is taken as the parallelism of the two measuring surfaces. When calibrating the lever caliper, one gauge block can be used to measure the parallelism of the two measuring surfaces in the same way. If the conclusions of the two calibration methods are inconsistent, in case of dispute, the calibration result of the parallel flat crystal shall prevail. Measuring surface
Figure 6 Extension rod
6.3.12 Indication indication value error and indication value change Figure 7 Gauge block position for parallelism calibration of two measuring surfaces For the indication indication value errors of graduation values ​​of 0.001mm, 0.002mm, and 0.005mm, use third-class, fourth-class, and fifth-class gauge blocks for calibration respectively.
Within ±10 divisions from the zero position of the dial, check one point every 2 divisions, and outside ±10 divisions, check one point every 10 divisions. The series sizes of the gauge blocks used are listed in Table 6. During the calibration, clamp an appropriate gauge block between the two measuring surfaces and align it to the zero position. Replace the gauge blocks in turn and read the readings of each inspected point on the indicator. For each inspected point, press the button 3 times, and take the arithmetic mean of the 3 readings as the reading value of the point. Substitute the reading value into the following formula to obtain the indication error of the point. 8
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