Some standard content:
National Metrology Verification Regulation of the People's Republic of China JJG 24-2003
Depth Micrometer
Customer Resources
Depth Micrometers
For reference only
Published on 2003-05-12
Implementation on 2003-11-12
Published by the General Administration of Quality Supervision, Inspection and Quarantine JJG24—2003
Verification Regulation of
Depth Micrometers
JJG 24--2003
Replaces JJG24—1986
This regulation was approved by the General Administration of Quality Supervision, Inspection and Quarantine on May 12, 2003, and came into effect on November 12, 2003.
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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
Qinghai Measuring Tools and Cutting Tools Co., Ltd.
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:
Liang Yuhong
Sun Defen
Zhang Liping
Participating drafters:
Yan Yonghong
Liu Wenbin
JJG 24—2003
(Xilongjiang Metrology Testing Institute)
(Harbin Metrology Verification and Testing Institute)
(Heilongjiang Metrology Verification and Testing Institute)
(Qinghai Measuring Tools and Cutting Tools Co., Ltd.)
(Heilongjiang Metrology Verification and Testing Institute)
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For reference only
References
3 Overview
4, Meter performance requirements
Line width and width difference
JJG 24—2003
4.2 Distance from the end edge of the cone of the differential cylinder to the scaled surface of the fixed sleeve4.3
Relative position of the end face of the chain face of the differential cylinder and the millimeter scale of the fixed sleeve4.4
Surface roughness of the measuring surface
Flatness of the measuring surface of the base
Indicator error
Working length of the replaceable measuring probe
4.9 Proofreading measuring tools
5 General technical requirements
5.1 Appearance
5.2 Interaction between various parts
6 Control of measuring instruments
6.1 Verification conditions
Verification items Appendix A Evaluation of the uncertainty of the measurement results of the indication error of the depth micrometer Appendix B Evaluation of the uncertainty of the measurement results of the working length of the interchangeable measuring rod of the depth micrometer Appendix C Format of the verification certificate and verification result notification (inside page) (1) 1 Scope JJG24—2003 Verification procedure for depth micrometers This procedure is applicable to the initial verification, subsequent verification and in-service inspection of depth micrometers with a division value of 0.01 mm and a measuring range of (0~300) mm.
References
This specification refers to the following documents:
JF1001+—1998 General metrological terms and definitions JJF1059-1999 Evaluation and expression of measurement uncertainty GB/T1218—1987 Depth micrometer
When using this specification, attention should be paid to the use of the current valid versions of the above-mentioned referenced documents. 3 Overview
The depth micrometer is a kind of equipment that uses the principle of screw pair transmission to convert rotary motion into linear motion. The depth micrometer consists of a differential cylinder, a fixed sleeve, a measuring disc rod, a base, a force measuring device, a locking device, etc., as shown in Figure 1.
Assume that there is no reference
【1-Force measuring device; 2-Differential sleeve: 3-Fixed sleeve: 4-Locking device: 5-Base: 6-Measuring device Depth micrometer is a measuring instrument used in the machinery manufacturing industry to measure the depth of the hole or mold of the workpiece and the height of the step.
As shown in Figure 2, there is a calibration gauge attached to the depth scale. 1
4 Metrological performance requirements
4.1 Graduation width and width difference
JJG24—2003
Figure 2 Calibration tool
The width of the longitudinal scale of the fixed sleeve and the scale on the differential cylinder is (0.15-0.20) mm: the difference in scale width should not exceed 0.03 mm.
4.2 The distance from the edge of the end face of the differential cone to the scaled surface of the fixed sleeve The distance from the edge of the end face of the differential cone to the scaled surface of the fixed sleeve should not exceed 0.4mmc4.3 The relative position of the end face of the differential cone and the millimeter scale of the fixed sleeve When the zero scale of the differential cylinder is aligned with the longitudinal scale of the fixed sleeve, the end face of the differential cylinder and the right edge of the millimeter scale of the fixed sleeve should be tangent. If not, the line should not exceed 0.05mm and the line should not exceed 0.1mm. 4.4 Surface roughness of measuring surface
The surface roughness of the measuring surface of the measuring rod, the measuring surface of the calibration gauge and the measuring surface of the base should not exceed R.0.05um. If the measuring surface of the measuring rod is made of cemented carbide, its surface roughness should not exceed R.0.10μm. 4.5 Flatness of the base measuring surface
The flatness of the base measuring surface should not exceed 0.002mm (excluding the range of 1mm from the edge). 4.6 Measuring forcewww.bzxz.net
The measuring force should be within the range of (3~6)N.
4.7 Indication error
The indication error of the micrometer should not exceed ±5um. Note: When the indication error of the depth micrometer in use exceeds ±5μm, but does not exceed ±10μm, it is allowed to continue to be used and it should be noted on the certificate.
4.8 Working length of the interchangeable measuring rod
The working length deviation of the interchangeable measuring rod shall not exceed the provisions of Table 1. 4.9 Proofreading gauge
The working size deviation and the parallelism of the two measuring surfaces of the proofreading gauge for the first calibration shall not exceed the provisions of Table 2. 2
JJG24—2003
Table 1 Working length deviation of interchangeable measuring rod
Working length of interchangeable measuring rod/mm
50~75.75~100
100 ~ 125, 125 - 150
150 - t75,175 ~ 200
200 ~225,225 ~250
250 ~ 275, 275 ~ 300
Deviation/ium
Table 2 Working size deviation of the calibration tool for the first calibration and the parallelism of the two measuring surfaces Nominal size/mm
100,125
150，175
200，223
250，275
Size deviation/pm
Parallelism of the two measuring surfaces m
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Note: When the calibration amount for subsequent calibration and inspection during use is guaranteed to be qualified for the parallelism of the two measuring surfaces: the working size is allowed to have a deviation and is used according to the actual size.
5 General Technical Requirements
5.1 Appearance
5.1.1 The working surface of the depth micrometer and the calibration gauge should not be rusted, dented or scratched, and the non-working surface should not have the coating peeling phenomenon. The scale lines should be clear, straight, uniform, without broken lines and other defects that affect the accuracy. 5.1.2 The depth micrometer should be marked with the manufacturer's name (or trademark), factory number, measurement range and mark. The calibration gauge and the replaceable measuring rod should be marked with the nominal size. 5.1.3
5.1.4 During the inspection and subsequent verification in use, the depth micrometer is allowed to have the above-mentioned appearance defects that do not affect the accuracy of use.
5.2 Interaction of various parts
The action of each moving part should be flexible, stable and without sticking. 5.2.1
5.2.2 The adjustment of the zero position should be smooth and reliable, and the locking device should be effective. 5.2.3 The replaceable measuring rod should be easy to replace and the fastening should be reliable. 5.2.4 The measuring rod should not have axial movement and radial swing that can be felt by hand. Measuring instrument control
Measuring instrument control includes initial calibration, subsequent calibration and in-use inspection. 3
6.1 Calibration conditions
6.1.1 Calibration equipment
The main calibration instruments are shown in Table 3.
6.1.2 Calibration environment conditions
JJG 24--2003
The temperature of the calibration room is (205)°C. Before calibration, the time for the micrometer to be tested to reach the temperature in the calibration room should be no less than 2 hours.
6.2 Verification items
Verification items are shown in Table 3.
Table 3 Verification items and main verification instruments list No.
Verification item
Interaction of each part
Grade width and width difference
Distance from the end shuttle edge of the differential cone to the
fixed sleeve scale surface
Relative position of the end face of the differential cone and the
fixed sleeve millimeter scale
Surface roughness of the measuring surface
Base measuring plate surface Flatness
Indication error
Working length of interchangeable measuring rod
Gauge for calibration
Main calibration instruments
Tool microscope
Grade 2 cold ruler or tool microscope
Surface roughness comparison sample
Or surface roughness meter
Grade 2 flat product or grade 0 knife edge ruler
Dynamometer with a graduation value not greater than
0.2N
2 Level flat crystal or level 0
flat plate 5 equal blocks
U=(0.5+5L)μm
4 equal blocks
U=(0.2+2L)μm
optical meter
4 equal mouse blocks
U=(0.2+2L)um
Note: "+" in the table means that it should be calibrated, and "_" means that it can be not calibrated. 6.3 Verification method
6.3.1 Appearance
Self-observation.
First verification
Verification category
Subsequent verification
In-use inspection
6.3.2 Interaction between various parts
Visual observation and test.
JJG24—2003
6.3.3 Graduation line width and width difference
On the tool microscope, randomly check at least three evenly distributed graduation lines on the differential cylinder and the fixed sleeve. The graduation line width difference is determined by the difference between the maximum value and the minimum value.
6.3.4 The distance from the end face of the differential cylinder cone to the graduation line surface of the fixed sleeve is calibrated on the tool microscope, or it can be calibrated by comparison method with a feeler gauge with a thickness of 0.4mm. The calibration should be carried out at no less than three positions within one rotation of the differential cylinder, as shown in Figure 3. The arbitration determination shall be based on the determination result on the tool microscope.
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6.3.5 Relative position of the end face of the differential cone and the millimeter scale of the fixed sleeve. After adjusting the micrometer to zero on the 2nd level flat product or the 0th level flat plate, observe whether the end face of the differential cone is tangent to the right edge of the millimeter scale of the fixed sleeve. If not, rotate the differential cylinder to make it tangent, and read the offset of its zero scale to the vertical scale of the fixed sleeve according to the differential cylinder. The offset is the value of offline or press line. See Figure 4. 45
Offline 0.02nm
Press line 0.02mm
6.3.6 Surface roughness of the measuring surface
Use the surface roughness comparison sample block to calibrate by comparison method, or use the surface roughness meter to calibrate. The arbitration calibration is based on the calibration result on the surface roughness comparison sample block. 6.3.7 Flatness of the base measuring surface
The first calibration of the depth micrometer is carried out by the technical light wave method using a 100mm diameter grade 2 flat product. 5
Other surface degree
In the formula: n is the number of fringes;
JJG 24—2003
——the wavelength of the working light wave, μm. For example, white light λ/2=0.3μm. The number of fringes shown in Figure 5 is 4 c
The subsequent calibration and in-use inspection of the depth micrometer is carried out by the 0-grade knife-edge ruler in the direction shown in Figure 6. (O)
6.3.8 Force measurement
Use a dynamometer with a graduation value not greater than 0.2N for calibration. 6.3.9 Indication error
Use 5 equal blocks to calibrate on a grade 2 flat product or a grade 0 flat plate. The inspection points should be evenly distributed at least at 5 points in the indication range, 5.12mm10.24mm (or 10.25mm), 15.36mm (or 15.37mm), 21.5mm, 25mm. Each inspection point must be calibrated with two sets of base blocks of the same size (the actual size difference does not exceed 2um), as shown in Figure 7.
The indication error e of each point is obtained by the following formula:
e= L, -L.
Where; L,——the reading value of the micrometer; L,——the actual size of the gauge block.
6.3.10 Working length of interchangeable measuring rod
In addition to first installing the [0, 25] mm measuring rod and calibrating according to the above 5 points, the depth dry micrometer should also install the other measuring rods in sequence without adjusting the zero position of the micrometer, and calibrate with two groups of 4 gauge blocks (the actual size difference does not exceed 1.2um) of the lower limit size of the measuring rod, which should meet the requirements of Table 1. 6.3.11 Proofreading gauge
For the dimensional deviation and parallelism of the two measuring surfaces of the proofreading gauge, the 4-equal-block comparison method is used to calibrate on the optical meter. The inspection points are shown in Figure 8. The difference between the maximum and minimum values is the parallelism of the two measuring surfaces. Handling of calibration results
A calibration certificate shall be issued to the depth micrometer that meets the requirements of this regulation after calibration; a calibration certificate shall be issued to the one that does not meet the requirements of this regulation6
1-block; 2-depth micrometer; 3-quality result notice, and indicate the unqualified items. 8
Calibration cycle
JJG 24-2003
The calibration cycle of the depth micrometer can be determined according to the actual use situation, generally not exceeding 1 year. Appendix A
A.1 Measurement method
JJG 24-2003
Evaluation of uncertainty of measurement result of indication error of depth micrometerThe indication error of the micrometer is calibrated by the direct method using 5 equal blocks. The following analysis of the uncertainty of the measurement result is based on the indication error of the 25mm point as an example. A.2 Mathematical model
The indication error of the depth micrometer:
e= L, - L, + L,'a -At -L,-a,-At, where:
L,—the reading value of the depth micrometer (under 20℃); L.
The actual size of the gauge block→ (under 20℃); and,
—are the linear expansion coefficients of the depth micrometer and the gauge block respectively; △ and △—are the values of the depth micrometer and the gauge block from the reference temperature of 20C respectively. A.3 Variance and sensitivity coefficient
Because A: and 4 are derived from the same thermometer and are related, the mathematical processing process is very complicated, so the following method is used to convert the related into the unrelated to simplify the mathematical processing process. a, - At - A ,2,, respectively represent L,. , the standard uncertainty u =u(e)=u, +i+(L-Ar)2-us +(t-α).uA.4 List of standard uncertainty
Standard uncertainty
Measurement component
Source of uncertainty
Measurement repeatability
Uncertainty of gauge block
Difference in linear expansion coefficient between depth micrometer and gauge block
Difference in overflow between depth micrometer and
gauge block
Standard uncertainty value
0.58×10-*9C
u. =0.39μm
L△t = 25 × 10 ×
La = 25 ×10' × 11.5
io-jm--t
Ver = 45
Te,l xu(xt)
2N force gauge
2nd level flat crystal or 0th level
flat plate5 equal blocks
U=(0.5+5L)μm
4 equal blocks
U=(0.2+2L)μm
Optical gauge
4 equal blocks
U=(0.2+2L)um
Note: "+" in the table means that it should be calibrated, and "_" means that it can be not calibrated. 6.3 Verification method
6.3.1 Appearance
Self-observation.
First verification
Verification category
Subsequent verification
In-use inspection
6.3.2 Interaction between various parts
Visual observation and test.
JJG24—2003
6.3.3 Graduation line width and width difference
On the tool microscope, randomly check at least three evenly distributed graduation lines on the differential cylinder and the fixed sleeve. The graduation line width difference is determined by the difference between the maximum value and the minimum value.
6.3.4 The distance from the end face of the differential cylinder cone to the graduation line surface of the fixed sleeve is calibrated on the tool microscope, or it can be calibrated by comparison method with a feeler gauge with a thickness of 0.4mm. The calibration should be carried out at no less than three positions within one rotation of the differential cylinder, as shown in Figure 3. The arbitration determination shall be based on the determination result on the tool microscope.
Online supply
6.3.5 Relative position of the end face of the differential cone and the millimeter scale of the fixed sleeve. After adjusting the micrometer to zero on the 2nd level flat product or the 0th level flat plate, observe whether the end face of the differential cone is tangent to the right edge of the millimeter scale of the fixed sleeve. If not, rotate the differential cylinder to make it tangent, and read the offset of its zero scale to the vertical scale of the fixed sleeve according to the differential cylinder. The offset is the value of offline or press line. See Figure 4. 45
Offline 0.02nm
Press line 0.02mm
6.3.6 Surface roughness of the measuring surface
Use the surface roughness comparison sample block to calibrate by comparison method, or use the surface roughness meter to calibrate. The arbitration calibration is based on the calibration result on the surface roughness comparison sample block. 6.3.7 Flatness of the base measuring surface
The first calibration of the depth micrometer is carried out by the technical light wave method using a 100mm diameter grade 2 flat product. 5
Other surface degree
In the formula: n is the number of fringes;
JJG 24—2003
——the wavelength of the working light wave, μm. For example, white light λ/2=0.3μm. The number of fringes shown in Figure 5 is 4 c
The subsequent calibration and in-use inspection of the depth micrometer is carried out by the 0-grade knife-edge ruler in the direction shown in Figure 6. (O)
6.3.8 Force measurement
Use a dynamometer with a graduation value not greater than 0.2N for calibration. 6.3.9 Indication error
Use 5 equal blocks to calibrate on a grade 2 flat product or a grade 0 flat plate. The inspection points should be evenly distributed at least at 5 points in the indication range, 5.12mm10.24mm (or 10.25mm), 15.36mm (or 15.37mm), 21.5mm, 25mm. Each inspection point must be calibrated with two sets of base blocks of the same size (the actual size difference does not exceed 2um), as shown in Figure 7.
The indication error e of each point is obtained by the following formula:
e= L, -L.
Where; L,——the reading value of the micrometer; L,——the actual size of the gauge block.
6.3.10 Working length of interchangeable measuring rod
In addition to first installing the [0, 25] mm measuring rod and calibrating according to the above 5 points, the depth dry micrometer should also install the other measuring rods in sequence without adjusting the zero position of the micrometer, and calibrate with two groups of 4 gauge blocks (the actual size difference does not exceed 1.2um) of the lower limit size of the measuring rod, which should meet the requirements of Table 1. 6.3.11 Proofreading gauge
For the dimensional deviation and parallelism of the two measuring surfaces of the proofreading gauge, the 4-equal-block comparison method is used to calibrate on the optical meter. The inspection points are shown in Figure 8. The difference between the maximum and minimum values is the parallelism of the two measuring surfaces. Handling of calibration results
A calibration certificate shall be issued to the depth micrometer that meets the requirements of this regulation after calibration; a calibration certificate shall be issued to the one that does not meet the requirements of this regulation6
1-block; 2-depth micrometer; 3-quality result notice, and indicate the unqualified items. 8
Calibration cycle
JJG 24-2003
The calibration cycle of the depth micrometer can be determined according to the actual use situation, generally not exceeding 1 year. Appendix A
A.1 Measurement method
JJG 24-2003
Evaluation of uncertainty of measurement result of indication error of depth micrometerThe indication error of the micrometer is calibrated by the direct method using 5 equal blocks. The following analysis of the uncertainty of the measurement result is based on the indication error of the 25mm point as an example. A.2 Mathematical model
The indication error of the depth micrometer:
e= L, - L, + L,'a -At -L,-a,-At, where:
L,—the reading value of the depth micrometer (under 20℃); L.
The actual size of the gauge block→ (under 20℃); and,
—are the linear expansion coefficients of the depth micrometer and the gauge block respectively; △ and △—are the values of the depth micrometer and the gauge block from the reference temperature of 20C respectively. A.3 Variance and sensitivity coefficient
Because A: and 4 are derived from the same thermometer and are related, the mathematical processing process is very complicated, so the following method is used to convert the related into the unrelated to simplify the mathematical processing process. a, - At - A ,2,, respectively represent L,. , the standard uncertainty u =u(e)=u, +i+(L-Ar)2-us +(t-α).uA.4 List of standard uncertainty
Standard uncertainty
Measurement component
Source of uncertainty
Measurement repeatability
Uncertainty of gauge block
Difference in linear expansion coefficient between depth micrometer and gauge block
Difference in overflow between depth micrometer and
gauge block
Standard uncertainty value
0.58×10-*9C
u. =0.39μm
L△t = 25 × 10 ×
La = 25 ×10' × 11.5
io-jm--t
Ver = 45
Te,l xu(xt)
2N force gauge
2nd level flat crystal or 0th level
flat plate5 equal blocks
U=(0.5+5L)μm
4 equal blocks
U=(0.2+2L)μm
Optical gauge
4 equal blocks
U=(0.2+2L)um
Note: "+" in the table means that it should be calibrated, and "_" means that it can be not calibrated. 6.3 Verification method
6.3.1 Appearance
Self-observation.
First verification
Verification category
Subsequent verification
In-use inspection
6.3.2 Interaction between various parts
Visual observation and test.
JJG24—2003
6.3.3 Graduation line width and width difference
On the tool microscope, randomly check at least three evenly distributed graduation lines on the differential cylinder and the fixed sleeve. The graduation line width difference is determined by the difference between the maximum value and the minimum value.
6.3.4 The distance from the end face of the differential cylinder cone to the graduation line surface of the fixed sleeve is calibrated on the tool microscope, or it can be calibrated by comparison method with a feeler gauge with a thickness of 0.4mm. The calibration should be carried out at no less than three positions within one rotation of the differential cylinder, as shown in Figure 3. The arbitration determination shall be based on the determination result on the tool microscope.
Online supply
6.3.5 Relative position of the end face of the differential cone and the millimeter scale of the fixed sleeve. After adjusting the micrometer to zero on the 2nd level flat product or the 0th level flat plate, observe whether the end face of the differential cone is tangent to the right edge of the millimeter scale of the fixed sleeve. If not, rotate the differential cylinder to make it tangent, and read the offset of its zero scale to the vertical scale of the fixed sleeve according to the differential cylinder. The offset is the value of offline or press line. See Figure 4. 45
Offline 0.02nm
Press line 0.02mm
6.3.6 Surface roughness of the measuring surface
Use the surface roughness comparison sample block to calibrate by comparison method, or use the surface roughness meter to calibrate. The arbitration calibration is based on the calibration result on the surface roughness comparison sample block. 6.3.7 Flatness of the base measuring surface
The first calibration of the depth micrometer is carried out by the technical light wave method using a 100mm diameter grade 2 flat product. 5
Other surface degree
In the formula: n is the number of fringes;
JJG 24—2003
——the wavelength of the working light wave, μm. For example, white light λ/2=0.3μm. The number of fringes shown in Figure 5 is 4 c
The subsequent calibration and in-use inspection of the depth micrometer is carried out by the 0-grade knife-edge ruler in the direction shown in Figure 6. (O)
6.3.8 Force measurement
Use a dynamometer with a graduation value not greater than 0.2N for calibration. 6.3.9 Indication error
Use 5 equal blocks to calibrate on a grade 2 flat product or a grade 0 flat plate. The inspection points should be evenly distributed at least at 5 points in the indication range, 5.12mm10.24mm (or 10.25mm), 15.36mm (or 15.37mm), 21.5mm, 25mm. Each inspection point must be calibrated with two sets of base blocks of the same size (the actual size difference does not exceed 2um), as shown in Figure 7.
The indication error e of each point is obtained by the following formula:
e= L, -L.
Where; L,——the reading value of the micrometer; L,——the actual size of the gauge block.
6.3.10 Working length of interchangeable measuring rod
In addition to first installing the [0, 25] mm measuring rod and calibrating according to the above 5 points, the depth dry micrometer should also install the other measuring rods in sequence without adjusting the zero position of the micrometer, and calibrate with two groups of 4 gauge blocks (the actual size difference does not exceed 1.2um) of the lower limit size of the measuring rod, which should meet the requirements of Table 1. 6.3.11 Proofreading gauge
For the dimensional deviation and parallelism of the two measuring surfaces of the proofreading gauge, the 4-equal-block comparison method is used to calibrate on the optical meter. The inspection points are shown in Figure 8. The difference between the maximum and minimum values is the parallelism of the two measuring surfaces. Handling of calibration results
A calibration certificate shall be issued to the depth micrometer that meets the requirements of this regulation after calibration; a calibration certificate shall be issued to the one that does not meet the requirements of this regulation6
1-block; 2-depth micrometer; 3-quality result notice, and indicate the unqualified items. 8
Calibration cycle
JJG 24-2003
The calibration cycle of the depth micrometer can be determined according to the actual use situation, generally not exceeding 1 year. Appendix A
A.1 Measurement method
JJG 24-2003
Evaluation of uncertainty of measurement result of indication error of depth micrometerThe indication error of the micrometer is calibrated by the direct method using 5 equal blocks. The following analysis of the uncertainty of the measurement result is based on the indication error of the 25mm point as an example. A.2 Mathematical model
The indication error of the depth micrometer:
e= L, - L, + L,'a -At -L,-a,-At, where:
L,—the reading value of the depth micrometer (under 20℃); L.
The actual size of the gauge block→ (under 20℃); and,
—are the linear expansion coefficients of the depth micrometer and the gauge block respectively; △ and △—are the values of the depth micrometer and the gauge block from the reference temperature of 20C respectively. A.3 Variance and sensitivity coefficient
Because A: and 4 are derived from the same thermometer and are related, the mathematical processing process is very complicated, so the following method is used to convert the related into the unrelated to simplify the mathematical processing process. a, - At - A ,2,, respectively represent L,. , the standard uncertainty u =u(e)=u, +i+(L-Ar)2-us +(t-α).uA.4 List of standard uncertainty
Standard uncertainty
Measurement component
Source of uncertainty
Measurement repeatability
Uncertainty of gauge block
Difference in linear expansion coefficient between depth micrometer and gauge block
Difference in overflow between depth micrometer and
gauge block
Standard uncertainty value
0.58×10-*9C
u. =0.39μm
L△t = 25 × 10 ×
La = 25 ×10' × 11.5
io-jm--t
Ver = 45
Te,l xu(xt)
5 Relative position of the end face of the differential cone and the millimeter scale of the fixed sleeve. After adjusting the micrometer to zero on the 2nd level flat product or the 0th level flat plate, observe whether the end face of the differential cone is tangent to the right edge of the millimeter scale of the fixed sleeve. If not, rotate the differential cylinder to make it tangent, and read the offset of its zero scale to the vertical scale of the fixed sleeve according to the differential cylinder. The offset is the value of offline or press line. See Figure 4. 45
Offline 0.02nm
Press line 0.02mm
6.3.6 Surface roughness of the measuring surface
Use the surface roughness comparison sample block to calibrate by comparison method, or use the surface roughness meter to calibrate. The arbitration calibration is based on the calibration result on the surface roughness comparison sample block. 6.3.7 Flatness of the base measuring surface
The first calibration of the depth micrometer is carried out by the technical light wave method using a 100mm diameter grade 2 flat product. 5
Other surface degree
In the formula: n is the number of fringes;
JJG 24—2003
——the wavelength of the working light wave, μm. For example, white light λ/2=0.3μm. The number of fringes shown in Figure 5 is 4 c
The subsequent calibration and in-use inspection of the depth micrometer is carried out by the 0-grade knife-edge ruler in the direction shown in Figure 6. (O)
6.3.8 Force measurement
Use a dynamometer with a graduation value not greater than 0.2N for calibration. 6.3.9 Indication error
Use 5 equal blocks to calibrate on a grade 2 flat product or a grade 0 flat plate. The inspection points should be evenly distributed at least at 5 points in the indication range, 5.12mm10.24mm (or 10.25mm), 15.36mm (or 15.37mm), 21.5mm, 25mm. Each inspection point must be calibrated with two sets of base blocks of the same size (the actual size difference does not exceed 2um), as shown in Figure 7.
The indication error e of each point is obtained by the following formula:
e= L, -L.
Where; L,——the reading value of the micrometer; L,——the actual size of the gauge block.
6.3.10 Working length of interchangeable measuring rod
In addition to first installing the [0, 25] mm measuring rod and calibrating according to the above 5 points, the depth dry micrometer should also install the other measuring rods in sequence without adjusting the zero position of the micrometer, and calibrate with two groups of 4 gauge blocks (the actual size difference does not exceed 1.2um) of the lower limit size of the measuring rod, which should meet the requirements of Table 1. 6.3.11 Proofreading gauge
For the dimensional deviation and parallelism of the two measuring surfaces of the proofreading gauge, the 4-equal-block comparison method is used to calibrate on the optical meter. The inspection points are shown in Figure 8. The difference between the maximum and minimum values is the parallelism of the two measuring surfaces. Handling of calibration results
A calibration certificate shall be issued to the depth micrometer that meets the requirements of this regulation after calibration; a calibration certificate shall be issued to the one that does not meet the requirements of this regulation6
1-block; 2-depth micrometer; 3-quality result notice, and indicate the unqualified items. 8
Calibration cycle
JJG 24-2003
The calibration cycle of the depth micrometer can be determined according to the actual use situation, generally not exceeding 1 year. Appendix A
A.1 Measurement method
JJG 24-2003
Evaluation of uncertainty of measurement result of indication error of depth micrometerThe indication error of the micrometer is calibrated by the direct method using 5 equal blocks. The following analysis of the uncertainty of the measurement result is based on the indication error of the 25mm point as an example. A.2 Mathematical model
The indication error of the depth micrometer:
e= L, - L, + L,'a -At -L,-a,-At, where:
L,—the reading value of the depth micrometer (under 20℃); L.
The actual size of the gauge block→ (under 20℃); and,
—are the linear expansion coefficients of the depth micrometer and the gauge block respectively; △ and △—are the values of the depth micrometer and the gauge block from the reference temperature of 20C respectively. A.3 Variance and sensitivity coefficient
Because A: and 4 are derived from the same thermometer and are related, the mathematical processing process is very complicated, so the following method is used to convert the related into the unrelated to simplify the mathematical processing process. a, - At - A ,2,, respectively represent L,. , the standard uncertainty u =u(e)=u, +i+(L-Ar)2-us +(t-α).uA.4 List of standard uncertainty
Standard uncertainty
Measurement component
Source of uncertainty
Measurement repeatability
Uncertainty of gauge block
Difference in linear expansion coefficient between depth micrometer and gauge block
Difference in overflow between depth micrometer and
gauge block
Standard uncertainty value
0.58×10-*9C
u. =0.39μm
L△t = 25 × 10 ×
La = 25 ×10' × 11.5
io-jm--t
Ver = 45
Te,l xu(xt)
5 Relative position of the end face of the differential cone and the millimeter scale of the fixed sleeve. After adjusting the micrometer to zero on the 2nd level flat product or the 0th level flat plate, observe whether the end face of the differential cone is tangent to the right edge of the millimeter scale of the fixed sleeve. If not, rotate the differential cylinder to make it tangent, and read the offset of its zero scale to the vertical scale of the fixed sleeve according to the differential cylinder. The offset is the value of offline or press line. See Figure 4. 45
Offline 0.02nm
Press line 0.02mm
6.3.6 Surface roughness of the measuring surface
Use the surface roughness comparison sample block to calibrate by comparison method, or use the surface roughness meter to calibrate. The arbitration calibration is based on the calibration result on the surface roughness comparison sample block. 6.3.7 Flatness of the base measuring surface
The first calibration of the depth micrometer is carried out by the technical light wave method using a 100mm diameter grade 2 flat product. 5
Other surface degree
In the formula: n is the number of fringes;
JJG 24—2003
——the wavelength of the working light wave, μm. For example, white light λ/2=0.3μm. The number of fringes shown in Figure 5 is 4 c
The subsequent calibration and in-use inspection of the depth micrometer is carried out by the 0-grade knife-edge ruler in the direction shown in Figure 6. (O)
6.3.8 Force measurement
Use a dynamometer with a graduation value not greater than 0.2N for calibration. 6.3.9 Indication error
Use 5 equal blocks to calibrate on a grade 2 flat product or a grade 0 flat plate. The inspection points should be evenly distributed at least at 5 points in the indication range, 5.12mm10.24mm (or 10.25mm), 15.36mm (or 15.37mm), 21.5mm, 25mm. Each inspection point must be calibrated with two sets of base blocks of the same size (the actual size difference does not exceed 2um), as shown in Figure 7.
The indication error e of each point is obtained by the following formula:
e= L, -L.
Where; L,——the reading value of the micrometer; L,——the actual size of the gauge block.
6.3.10 Working length of interchangeable measuring rod
In addition to first installing the [0, 25] mm measuring rod and calibrating according to the above 5 points, the depth dry micrometer should also install the other measuring rods in sequence without adjusting the zero position of the micrometer, and calibrate with two groups of 4 gauge blocks (the actual size difference does not exceed 1.2um) of the lower limit size of the measuring rod, which should meet the requirements of Table 1. 6.3.11 Proofreading gauge
For the dimensional deviation and parallelism of the two measuring surfaces of the proofreading gauge, the 4-equal-block comparison method is used to calibrate on the optical meter. The inspection points are shown in Figure 8. The difference between the maximum and minimum values is the parallelism of the two measuring surfaces. Handling of calibration results
A calibration certificate shall be issued to the depth micrometer that meets the requirements of this regulation after calibration; a calibration certificate shall be issued to the one that does not meet the requirements of this regulation6
1-block; 2-depth micrometer; 3-quality result notice, and indicate the unqualified items. 8
Calibration cycle
JJG 24-2003
The calibration cycle of the depth micrometer can be determined according to the actual use situation, generally not exceeding 1 year. Appendix A
A.1 Measurement method
JJG 24-2003
Evaluation of uncertainty of measurement result of indication error of depth micrometerThe indication error of the micrometer is calibrated by the direct method using 5 equal blocks. The following analysis of the uncertainty of the measurement result is based on the indication error of the 25mm point as an example. A.2 Mathematical model
The indication error of the depth micrometer:
e= L, - L, + L,'a -At -L,-a,-At, where:
L,—the reading value of the depth micrometer (under 20℃); L.
The actual size of the gauge block→ (under 20℃); and,
—are the linear expansion coefficients of the depth micrometer and the gauge block respectively; △ and △—are the values of the depth micrometer and the gauge block from the reference temperature of 20C respectively. A.3 Variance and sensitivity coefficient
Because A: and 4 are derived from the same thermometer and are related, the mathematical processing process is very complicated, so the following method is used to convert the related into the unrelated to simplify the mathematical processing process. a, - At - A ,2,, respectively represent L,. , the standard uncertainty u =u(e)=u, +i+(L-Ar)2-us +(t-α).uA.4 List of standard uncertainty
Standard uncertainty
Measurement component
Source of uncertainty
Measurement repeatability
Uncertainty of gauge block
Difference in linear expansion coefficient between depth micrometer and gauge block
Difference in overflow between depth micrometer and
gauge block
Standard uncertainty value
0.58×10-*9C
u. =0.39μm
L△t = 25 × 10 ×
La = 25 ×10' × 11.5
io-jm--t
Ver = 45
Te,l xu(xt)
+ L,'a -At -L,-a,-At, where:
L,—the reading value of the depth micrometer (under 20℃); L.
the actual size of the gauge block → (under 20℃); and,
—are the linear expansion coefficients of the depth micrometer and the gauge block respectively; △ and △—are the values of the depth micrometer and the gauge block from the reference temperature of 20C. A.3 Variance and sensitivity coefficient
Because A: and 4 are related from the same thermometer, the mathematical processing process is very complicated, so the following method is used to convert the related into the unrelated to simplify the mathematical processing process. a, - At - A ,2,, respectively represent L,. , the standard uncertainty u =u(e)=u, +i+(L-Ar)2-us +(t-α).uA.4 List of standard uncertainty
Standard uncertainty
Measurement component
Source of uncertainty
Measurement repeatability
Uncertainty of gauge block
Difference in linear expansion coefficient between depth micrometer and gauge block
Difference in overflow between depth micrometer and
gauge block
Standard uncertainty value
0.58×10-*9C
u. =0.39μm
L△t = 25 × 10 ×
La = 25 ×10' × 11.5
io-jm--t
Ver = 45
Te,l xu(xt)
+ L,'a -At -L,-a,-At, where:
L,—the reading value of the depth micrometer (under 20℃); L.
the actual size of the gauge block → (under 20℃); and,
—are the linear expansion coefficients of the depth micrometer and the gauge block respectively; △ and △—are the values of the depth micrometer and the gauge block from the reference temperature of 20C. A.3 Variance and sensitivity coefficient
Because A: and 4 are related from the same thermometer, the mathematical processing process is very complicated, so the following method is used to convert the related into the unrelated to simplify the mathematical processing process. a, - At - A ,2,, respectively represent L,. , the standard uncertainty u =u(e)=u, +i+(L-Ar)2-us +(t-α).uA.4 List of standard uncertainty
Standard uncertainty
Measurement component
Source of uncertainty
Measurement repeatability
Uncertainty of gauge block
Difference in linear expansion coefficient between depth micrometer and gauge block
Difference in overflow between depth micrometer and
gauge block
Standard uncertainty value
0.58×10-*9C
u. =0.39μm
L△t = 25 × 10 ×
La = 25 ×10' × 11.5
io-jm--t
Ver = 45
Te,l xu(xt)
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