This regulation is applicable to the initial verification, subsequent verification and in-use inspection of squares. JJG 7-2004 Verification Regulation for Squares JJG7-2004 Standard download decompression password: www.bzxz.net
This regulation is applicable to the initial verification, subsequent verification and in-use inspection of squares.
Some standard content:
National Metrology Verification Regulation of the People's Republic of China JJG7—2004 Squares Promulgated on 2004-03-02 Implementation on 2004-09-02 Promulgated by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, JJG7—2004 Verification Regulation ofSquares JJG7—2004 Replaces JJG61—1980 JJG7—1986 This regulation was approved by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China on March 2, 2004, and came into effect on September 2, 2004. Responsible unit: Main drafting unit: Participating drafting unit: National Technical Committee for Geometric and Angle Metrology Shaanxi Institute of Metrology and Testing Xi'an University of Architecture and Technology CESI Metrology and Testing Center Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences This regulation is entrusted to the National Technical Committee for Geometric and Angle Metrology to be responsible for the interpretation of this regulation. Main drafters: Wang Caixia Wang Ping'an Participating in the drafting Strawman: Li Jiangyun Liu Yanan JJG7—2004 (Shaanxi Institute of Metrology and Testing) (Shaanxi Institute of Metrology and Testing) (Xi'an University of Architecture and Technology) (Shaanxi Institute of Metrology and Testing) (CESI Metrology and Testing Center) (Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences) Scope· References 3 Overview 4 Planning Measuring performance requirements JJG7—2004 4.1 Surface roughness of measuring surface, base surface and side surface4.2 Flatness of measuring surface and base surface Straightness of measuring surface Parallelism between base surfaces Verticality of side surface relative to base surface. 5Verticality of α and β angle measuring surface relative to base surface4.6 Indication error of linear steel square General technical requirements 6 Control of measuring instruments|| tt||Verification conditions Verification items· Verification methods· Handling of verification results Verification cycle Appendix A Gap method and direct measurement method Appendix B Format of the inner pages of the verification certificate Appendix C Format of the inner pages of the verification result notification 1 Scope JJG7—2004 Verification procedure for square rulers This procedure applies to the initial verification, subsequent verification and in-use inspection of square rulers. 2 References This specification refers to the following documents JJF1001—1998 General metrological terms and definitions JJF1059—1999 Evaluation and expression of measurement uncertainty JJF1094—2002 Evaluation of measuring instrument characteristics GB/T6092—2004 Square When using this specification, attention should be paid to using the current valid versions of the above referenced documents. 3 Overview The square is a commonly used measuring tool in inspection and marking work. It is used to check the verticality of the workpiece or to calibrate the verticality of the longitudinal and transverse guide rails of the instrument and machine tool. It is usually made of steel, cast iron or granite. According to its structural form, it can be divided into cylindrical square (Figure 1), rectangular square (Figure 2), triangular square (Figure 3), knife-edge square (Figure 4), cast iron square (Figure 5), wide seat square (Figure 6), flat square (Figure 7), and line steel square (Figure 8). Its basic dimensions, accuracy levels and indication errors are shown in Tables 1 to 8 respectively. Measuring pad surface Cylindrical square Table 1 Basic dimensions and accuracy levels of cylindrical squares Accuracy level Basic dimensions 00 level, 0 level Measuring scene surface Rectangular square Knife-edge rectangular square Accuracy level Basic dimensions JJG7—2004 Measuring egg surface Figure 2 Rectangular square Table 2 Basic dimensions and accuracy levels of rectangular squares Accuracy level Basic dimensions Accuracy level Basic dimensions Measuring surface Side,|| tt||Figure 3 Triangular square 00 grade, 0 grade, 1 grade 00 grade, 0 grade Basic dimensions and accuracy grades of triangular squares00 grade, 0 grade, 1 grade Knife-edge square Wide seat knife-edge right angle Cast iron square Measuring surface Such as measuring surface JJG7—2004 Figure 4 Knife-edge square Measuring surface Table 4 Basic dimensions and accuracy grades of knife-edge squaresAccuracy grades Basic dimensions Accuracy grades Basic dimensions 0 grade, 1 grade|| tt||Grade 0, Grade 1 Table 5 Basic dimensions and accuracy grades of cast iron squaresAccuracy grades Basic dimensions Figure 5 Cast iron squares Grade 0, Grade 1 Measuring surface Figure 6 Wide seat squaresWww.bzxZ.net Accuracy grades Plane right angle Ruler and flat Surface right angle ruler with seat Basic dimension H Indication error JJG7—2004 Table 6 Basic dimensions and accuracy grades of wide seat squaresGrade 0 Figure 7 Flat squares Table 7 Basic dimensions and accuracy grades of flat squares Accuracy level Measuring surface Grade 0, Grade 1, Grade 2 Tide crab surface Figure 8 Linear steel square Basic dimensions and indication error of linear steel square150 Measuring surface dimensions >500~1600 Measuring surface dimensions JJG7—2004 Table 9 Surface roughness of measuring disk surface, base surface and side surface Surface roughness of measuring surface and base surface R,/um0 level Verticality of measuring disk surface and base surface, α, βVerticality of measuring surface relative to base surface/μm Note: The flatness of the base surface is not allowed to be convex. Linear steel square Surface roughness R./um Flatness, straightness and parallelism Flatness or straightness/um Parallelism between base surfaces/um Verification items JJG7-2004 Flatness of cast iron squareNumber of scraped contact pointsGrade 0 Number of contact points in a square area of 25mm×25mmDifference in the number of contact points in any two squares (25mm×25mm)Table 12 Size of measuring surface H ≥25 points Accuracy level Vertical of linear steel square Degree, flatness, straightness and parallelism Perpendicularity of measuring surface to base surface Size of measuring surface H/mm Flatness or straightness of measuring surface Perpendicularity of side surface to base surface Perpendicularity of side surface to base surface/um ≥20 points Parallelism between base surfaces Size of measuring surface 1/mm Metrological performance requirements JJG7—2004 Table 13 (continued) Perpendicularity of side surface to base surface/um Surface roughness of measuring surface, base surface and side surface 4.1 Should not exceed the requirements of Table 9. 4.2 Flatness of measuring surface and base surface 4.2.1 The flatness of the square rulers of the structural forms of Figures 1 to 7 shall not exceed the requirements of Table 10. 4.2.2 The number of scraping contact points for the flatness of cast iron squares is shown in Table 11. 4.2.3 The flatness of wire-grained steel squares shall not exceed the provisions of Table 12. 4.3 Straightness of measuring surface The straightness of squares in the structural form of Figure 1, Figure 2 (b), and Figure 4 shall not exceed the provisions of Table 10. The straightness of wire-grained steel squares shall not exceed the provisions of Table 12. 4.4 Parallelism between base surfaces The parallelism of squares in the structural form of Figure 4, Figure 6, and Figure 7 shall not exceed the provisions of Table 10. The parallelism of wire-grained steel squares shall not exceed the provisions of Table 12. 4.5 Verticality of side surface relative to base surface The verticality of square rulers of the structure of Figures 2 to 7 shall not exceed the provisions of Table 13. 4.6 Verticality of α and β angle measuring surface relative to base surface The verticality of square rulers of the structure of Figures 1 to 7 shall not exceed the provisions of Table 10. Linear steel square rulers shall not exceed the provisions of Table 12. 4.7 Indication error of linear steel square rulers The indication error of the line from any scale line to the edge or end of the ruler shall not exceed the provisions of Table 8. 5 General technical requirements 5.1 Newly manufactured square rulers shall not have defects such as rust, magnetism, bruises, cracks, sand holes, burrs, etc. The non-working surface of cast iron square rulers shall be sand-cleaned and painted. JJG7-2004 5.2 The non-working surface of the square ruler must have the manufacturer's name or trademark, MC mark and factory number. 5.3 For the square rulers that are subsequently calibrated and inspected during use, appearance defects that do not affect the measurement accuracy are allowed. 6 Control of measuring instruments Control of measuring instruments includes: initial calibration, subsequent calibration and inspection during use. 6.1 Calibration conditions 6.1.1 Environmental conditions 6.1.1.1 Indoor temperature (20±5)℃ 6.1.1.2 Temperature equilibration time is not less than 2h. 6.1.1.3 Before calibration, the square ruler to be inspected and the calibration equipment should be placed on the flat plate at the same time. 6.1.2 Calibration equipment See Table 14 for calibration equipment. Table 14 List of calibration equipment Name of standard instrument Surface roughness comparison sample Knife edge ruler Micrometer Straight collimator Standard square iron Wide seat square Cylindrical square Grinding surface flat ruler Micrometer Lever caliper Steel ruler Straight ruler R.( 0.10~1.60)μm ≤2000mm ≤500mm Graduation value 0.001mm ≤500mm (0.02~0.50)mm ≤1000mm (0~1)mm ≤200mm ≤2000mm Note: "MPE" in the table means maximum permissible indication error. 9 Technical requirements 00 grade, 0 grade, 1 grade, 2 grade 0 grade, 1 grade 1 grade or 4 grade MPE≤+1μm Mutual verticality≤1.5m 00 grade, 0 grade Flatness≤1um Indication error≤5μm MPEg+2um MPEg≤±0.15mm Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.