Some standard content:
National Standard of the People's Republic of China
Electronic Digital Calipers
Calipcrs with electronic digital display1Subject Content and Scope of Application
GB/T 14899 94
This standard specifies the terminology, product classification, technical requirements, test methods, inspection methods, marking and packaging of electronic digital calipers. This standard applies to electronic digital calipers with a resolution of 0.01mm and a maximum measuring range of 500mm. 2 Reference standards
GB2423.3 Basic environmental test procedures for electrical products Test Ca: Constant damp heat test method GB2123.22 Basic environmental test procedures for electrical and electronic products Test N: Temperature change test method
GB4986 Cast iron plate
GB6091
Knife-edge ruler
GB6093 Gauge block
3 Terminology
3.1 Electronic digital caliper
A length measuring tool that uses the principle of electronic digital display to read the distance between the two measuring claws moving relative to each other 3.2 Resolution
The electronic digital caliper can display the minimum change value of the measured value. 4 Product classification
4.1 Type
The recommended types of electronic digital calipers are I, 1, Ⅱ, and N (see Figures 1 to 4). [
「Type electronic digital caliper
1·- Ruler body; 2 Knife 11-shaped internal measuring jaws 3
3 Ruler frame; 4 Fastening screws; 5 Display; 6 Output terminal 11; 7~- Depth gauge; 8-- Function button; 9 External measuring jaws Approved by the State Administration of Technical Supervision on January 5, 1994 and implemented on October 1, 1994
GB/T 14899-94
Figure 2 Type II electronic digital caliper
1 Ruler body; 2 Knife-shaped inner measuring jaws; 3 Ruler frame; 4 Fastening screws; 5 Display; 6 Output port; 7 Function button; 8 External measuring jaws Figure 3 Type II electronic digital caliper
1 Ruler body; 2 Knife-shaped outer measuring jaws; 3 Fastening screws; 4 Display; 5 Output port; 6 Ruler frame; Function button; Inner and outer measuring jaws GB/T14899-94
Figure 4 Type N electronic digital caliper
1 Ruler body: 2 Fastening screws; 3-Display; 4-Output port; 5-Ring; 6-Function button; 7 Inner and outer measuring jaws
Note: Figures 1 to 4 are only for illustration 4.2 Measuring range
The types of electronic digital calipers and the corresponding measuring ranges are shown in Table 1. Table 1
4.3 Structural dimensions
Measuring range
0~-150
0--200
0～200
0~~300
The extended length of the measuring jaws of the electronic digital caliper and the combined width of the arc-shaped inner measuring jaws shall comply with the provisions of Table 2. Table 2
The maximum extended length of the outer measuring jaws
Measuring range
0～200bZxz.net
0～300
0～500
Minimum extended length
Inner Measuring jaws minimum extended length 12 arc-shaped knife-edge external measurement minimum extended length 1 arc-shaped internal measurement width 6 10 or 20 5 Technical requirements GB/T14899-94 5.1 Electronic digital calipers shall not have external defects that affect their use. 5.2 The scale frame of the electronic digital caliper shall be able to move smoothly along the scale body without stagnation or looseness. Each button shall be flexible and reliable. 5.3 The hardness of the measuring surface of the electronic digital caliper shall not be lower than that specified in Table 3. Table 3 Internal and external measurement Measuring surface of the electronic digital caliper
Other measuring surfaces
Carbon steel or tool steel,
Stainless steel
Carbon steel, tool steel, stainless steel
5.4 The maximum allowable value of the surface roughness R of the measuring surface of the electronic digital caliper is shown in Table 4 Table 4
Inner measuring jaw measuring surface
Outer measuring jaw measuring surface
5.5 The inner and outer measuring jaws of the electronic digital caliper shall have the same extended length after being combined. 5.6 The flatness tolerance of the measuring surface of the outer measuring jaw of the electronic digital caliper is 0.002mm Note: The range of 0.2mm from the edge of the measuring surface is not included, hardness
664HV(58HRC)
551HV(-52. 5HRC)
377HV(40HRC)
Other measuring surfaces
5.7 For the measuring surface of the outer measuring jaw of the electronic digital caliper, whether the scale frame is tightened or not, its parallelism tolerance is shown in Table 5. Table 5
Measuring range
Maximum gap after the outer measuring jaws are combined
5.8 The dimensional deviation of the arc-shaped inner measuring jaw of the electronic digital caliper is 619:01. The parallelism between the two measuring surfaces at any position in the measuring range
5.9 For the electronic digital caliper with knife-shaped inner measuring jaws, when the distance between the measuring surfaces of the outer measuring jaws is adjusted to 10mm, the dimensional deviation and parallelism tolerance of the knife-shaped inner measuring jaws are shown in Table 6. Table 6
Deviation of the inner measuring jaws in the knife-edge shape
Parallelism
The minimum deviation of the inner measuring jaws in Table 6 refers to the difference between the value measured in the direction parallel to the ruler body and the 10mm gauge block. The difference between the value measured in any other direction and the 10mm gauge block shall not exceed the upper deviation of the inner measuring jaws. 5.10 The indication error of the external measurement of the electronic digital caliper and the indication error of the measurement depth and step size of 20mm shall not exceed the provisions of Table 7 regardless of whether the ruler plate is tightened or not.
Measurement length
≥200～300
300～500
5.11 The indication variability of the electronic digital caliper shall not exceed 0.01mm. 32
Coefficient error
GB/T 14899—94
5.12 The numerical drift of the two measuring surfaces of the electronic digital caliper at any position shall not exceed 0.01mm. 5.13 The working environment humidity of the electronic digital caliper shall be 0～40℃. 5.14 The current consumption of the electronic digital caliper shall not exceed 25μA. 5.15 The maximum speed of the scale frame of the electronic digital caliper is 1m/s. 6 Test method
6.1 The high and low temperature test of the electronic digital caliper shall be in accordance with GB2423.22. 6.2 The damp heat test of the electronic digital caliper shall be in accordance with GB2423.3. Inspection method
The inspection method is shown in Appendix A (Supplement).
8 Marking and packaging
8.1 Marking
8.1.1 The electronic digital caliper shall be marked with:
Manufacturer's name or registered trademark;
Product serial number.
8.1.2 The packaging box shall be marked with:
Manufacturer's name or registered trademark;
b. Product name;
Measuring range.
8.2 Packaging
Electronic digital calipers shall be treated with rust prevention before packaging and properly packaged. The product shall not be damaged during transportation due to poor packaging. 8.3 Electronic digital calipers that meet the requirements of this standard after inspection shall be accompanied by an instruction manual and a product certificate. The product certificate shall be marked with the standard number of this standard, the product serial number and the date of manufacture. 33
GB/T14899-94
Appendix A
Testing method of electronic digital caliper
(Supplement)
This appendix is about the test method of electronic digital caliper for factory inspection. A1 Test conditions
When testing electronic digital caliper, the room temperature should be 20±5℃ and the relative humidity should not be more than 80%. A2 Appearance
Force observation.
A3 Interaction
A3.1 When the ruler frame is moved along the ruler body, it should feel stable without sticking or looseness. If there is any objection, the relative moving force between the ruler frame and the ruler body should be measured with a spring dynamometer. The moving force and the change of moving force should not exceed the requirements of Table A1. Table A1
Measurement range
0~~500
Moving force
8~15
Moving force change
A3.2 When the ruler frame is moved along the ruler body, it should feel stable, and there should be no obvious shaking of the ruler frame relative to the ruler body. If there is any objection, the following test method shall be used for testing, and the shaking amount shall not exceed the provisions of Table A2. A2
Measurement range
Shaking pad
0~~200
0～300
During the test, the electronic digital caliper measuring jaws shall be placed vertically upward and supported. At this time, the dial indicator measuring head shall contact the side of the outer measuring jaw at a distance of 10mn from the end face of the outer measuring jaw. Then, a spring dynamometer shall be used to apply force twice in positive and negative directions according to the force value given in Table A3. The difference between the two readings of the dial indicator is the shaking amount.
Measurement range
0～200
0～300
0～500
A3.3 The push button should be flexible and not stuck. Repeat the operation five times and the display function should be normal. A4 Measuring surface hardness
Force value
Measured on Vickers hardness tester (or Rockwell hardness tester). Each product sampled can be hit at one point, and then hit evenly distributed points, and the arithmetic mean of three points is taken as the test result. 34
A5 Measuring surface surface roughness
GB/T 14899--94
Compare visually with surface roughness comparison sample. If there is any objection, measure with surface roughness inspection instrument. A6 The difference in the extended length of the two measuring claws
Observe visually. If there is any objection, use tool microscope to detect again, and it should meet the requirements of Table A4. Table A4
External measuring jaws, extension length difference
A7 Measuring surface flatness
Internal measuring jaw extension length difference
Use a grade 0 blade ruler (according to GB6091) to inspect the long side, short side and diagonal position of the measuring surface by the light gap method. A8 Combined gap of external measuring surface and parallelism between two external measuring surfaces A8.1 Combined gap
Move the ruler frame so that the measuring surfaces of the two measuring jaws are in contact with each other. Tighten and loosen the fastening screws respectively, and observe the light gap between the measuring surfaces. A8.2 Parallelism
Insert special gauge blocks of different sizes (according to GB6093) between the two external measuring surfaces for inspection. During the inspection, each ruler should detect the difference between the maximum and minimum readings at the inner and outer ends of the measuring surface. A9 Dimensional deviation of arc-shaped inner measuring jaws
Move the ruler frame to make the measuring surface of the outer measuring jaws touch the hand, and use the outer diameter dry micrometer to measure along the measuring jaws in the direction parallel to the ruler body. When measuring in other directions, the measured deviation should not exceed the upper deviation of 6 values. A10 Dimensional deviation and parallelism of knife-edge shaped inner measuring jaws A10.1 Ruler deviation
Place a 10mm gauge block with a level 3 accuracy flat between the measuring surfaces of the two outer measuring jaws, move the ruler frame to make it touch the hand, tighten the screws, and then use the micrometer to detect the length of the knife-edge shaped inner measuring surface. When inspecting the root of the inner measuring melon, the contact length of the dry micrometer measuring surface and the knife-edge shaped inner measuring surface should not exceed 3mm.
A10.2 Parallelism
Detect along the inner and outer ends of the knife-shaped inner measuring jaw measuring surface, and the difference between the maximum and minimum reading values. A11 Indication error
A11.1 Indication error of external measurement
Move the ruler frame to make the two measuring surfaces touch each other, set the digital display to zero, put a set of gauge blocks with a dimensional series of level 3 accuracy specified in Table A5 between the two measuring surfaces of the digital display ruler for detection, measure the difference between the displayed value of each point and the gauge block size, connect the deviations of each point to make a curve, and the difference between the highest point and the lowest point on the vertical coordinate. 35
Measuring range
0~-200
GB/T 14899
9—94
Gauge block size series
5,10,15.20.25.30.35,40,45,50.60.70,80.90,100.110,120.130.140,15010,20.30,40.50.60,70.80,90.100,110,120,130,140,150,160,170,180,190,20015,30,45.60, 75,90,105,120,135,150,165,180,195,210,225,240,255,270,285,300 25.5 0.75,100,125,150,175,200,225.25 0.275,300,325.350,375,400.425.450.175,500 A11.2 Depth and step indication error || tt || Use a 20mm grade 3 precision gauge block to set the grade 1 cast iron plate (according to GB4986), the measuring surface at the tail of the electronic digital caliper with a depth gauge and the step measuring surface at the front end of the scale frame are respectively in contact with the measuring surface of the gauge block, and the difference between the displayed value and the gauge block size when the depth gauge and the step measuring surface are respectively in contact with the flat plate. A12 Indication variability
Without any change in the measurement conditions, repeatedly move the scale frame so that the two measuring melon measuring surfaces are in contact with each other five times, and the maximum difference in the displayed value.
A13 Numerical drift
Move the scale frame to any position, tighten the scale frame, The digital display value is kept for 1 hour, and the change of its value is observed. A14 Current consumption
Use a special sheet detector to detect.
A15 Moving speed
Use manual speed simulation, and observe whether the digital display is normal after moving the ruler frame. Additional remarks:
This standard is proposed by the Ministry of Machinery Industry of the People's Republic of China. This standard is under the jurisdiction of the National Technical Committee for Standardization of Measuring Tools and Measuring Instruments. This standard is drafted by Shanghai Measuring Tools and Cutting Tools Factory. The main drafters of this standard are Jin Mingsheng, Wang Gu, Yang Shuzhen, and Jin Shangzhi. 36130.140,15010,20.30,40.50.60,70.80,90.100,110,120,130,140,150,160,170,180,190, 20015,30,45.60,75,90,105,120,135,150,165,180,195,210,225,240,255,270,285,30025. 50.75,100,125,150,175,200,225.250.275,300,325.350,375,400.425.450.175,500A11.2 Depth and step indication error
Place a 20mm grade 3 precision gauge block on a grade 1 cast iron plate (according to GB4986) and set the depth gauge The measuring surface of the tail of the electronic digital caliper and the measuring surface of the step at the front of the scale frame are divided into The difference between the displayed value and the gauge block size when the moving depth gauge and the step measuring surface are in contact with the flat plate. A12 indication variability
When the measuring conditions are not changed, the moving ruler is repeated. The frame makes the two measuring melons touch the measuring surface five times, and the maximum difference in the displayed value.
A13 numerical drift
Move the ruler frame to any position, tighten the ruler frame, and the digital display shows the value Keep for 1 hour and observe the change of its value. A14 Current consumption
Use a special film detector to detect.
A15 Moving speed
Use manual speed simulation and observe the digital display after moving the ruler frame Is it normal? Additional remarks:
This standard is proposed by the Ministry of Machinery Industry of the People's Republic of China. This standard is under the jurisdiction of the National Technical Committee for Standardization of Measuring Tools and Measuring Instruments. This standard was drafted by Shanghai Measuring Tools and Cutting Tools Factory. The main drafter of this standard is Jin Mingsheng, Wang Gu, Yang Shuzhen, Jin Shangzhi. 36130.140,15010,20.30,40.50.60,70.80,90.100,110,120,130,140,150,160,170,180,190, 20015,30,45.60,75,90,105,120,135,150,165,180,195,210,225,240,255,270,285,30025. 50.75,100,125,150,175,200,225.250.275,300,325.350,375,400.425.450.175,500A11.2 Depth and step indication error
Place a 20mm grade 3 precision gauge block on a grade 1 cast iron plate (according to GB4986) and set the depth gauge The measuring surface of the tail of the electronic digital caliper and the measuring surface of the step at the front of the scale frame are divided into The difference between the displayed value and the gauge block size when the moving depth gauge and the step measuring surface are in contact with the flat plate. A12 indication variability
When the measuring conditions are not changed, the moving ruler is repeated. The frame makes the two measuring melons touch the measuring surface five times, and the maximum difference in the displayed value.
A13 numerical drift
Move the ruler frame to any position, tighten the ruler frame, and the digital display shows the value Keep for 1 hour and observe the change of its value. A14 Current consumption
Use a special film detector to detect.
A15 Moving speed
Use manual speed simulation and observe the digital display after moving the ruler frame Is it normal? Additional remarks:
This standard is proposed by the Ministry of Machinery Industry of the People's Republic of China. This standard is under the jurisdiction of the National Technical Committee for Standardization of Measuring Tools and Measuring Instruments. This standard was drafted by Shanghai Measuring Tools and Cutting Tools Factory. The main drafter of this standard is Jin Mingsheng, Wang Gu, Yang Shuzhen, Jin Shangzhi. 36
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