1、BRITISH STANDARD BS 6393:1987 ISO 5436:1985 Specification for Calibration of stylus instruments ISO title: Calibration specimens Stylus instruments Types, calibration and use of specimens UDC 53.089.68BS6393:1987 This British Standard, having been prepared under the directionof the General Mechanica
2、l Engineering Standards Committee, was published under the authority ofthe Board of BSI and comes intoeffect on 27 February 1987 BSI 07-1999 First published December 1983 First revision February 1987 The following BSI references relate to the work on this standard: Committee reference GME/10 Draft f
3、or comment 83/74368 DC ISBN 0 580 15561 7 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the General Mechanical Engineering Standards Committee (GME/-) to Technical Committee GME/10 upon which the following bodies were represented: Departme
4、nt of Trade and Industry (National Engineering Laboratory) Department of Trade and Industry (National Physical Laboratory) GAMBICA (BEAMA Ltd.) Gauge and Tool Makers Association Institution of Production Engineers Loughborough University of Technology Ministry of Defence University of Warwick Coopte
5、d member Amendments issued since publication Amd. No. Date of issue CommentsBS6393:1987 BSI 07-1999 i Contents Page Committees responsible Inside front cover National foreword ii 1 Scope and field of application 1 2 References 1 3 Definitions 1 4 Types and purposes of instrument calibration specimen
6、s 1 5 Materials 2 6 Size of specimen 2 7 Mechanical requirements 3 8 Basis of assessment of calibrated values 7 9 Marking 8 Annex A Calibration of instrument calibration specimens 10 Annex B Use of instrument calibration specimens 12 Annex C Reference conditions, error and statements 20 Figure 1 Typ
7、e A1 groove 3 Figure 2 Type A2 groove 3 Figure 3 Type B2 grooves (sensitive grid) 4 Figure 4 Type B2 grooves (insensitive grid) 4 Figure 5 Type C1 grooves 5 Figure 6 Type C2 grooves 6 Figure 7 Type C3 grooves 6 Figure 8 Type C4 grooves 6 Figure 9 Type D grooves (profile repetition at 4 mm intervals)
8、 7 Figure 10 Assessment of calibrated values for type A1 8 Figure 11 Profile graphs 10 Figure 12 Gauge blocks providing a series of steps 10 Figure 13 Choice of sampling length 11 Figure 14 Effects of horizontal magnification 12 Figure 15 Transmission characteristic for calibration 13 Figure 16 R at
9、ransmission curves characteristic of types C1, C2 and C4 specimens conforming to ISO 3274 14 Figure 17 Stylus wear 15 Figure 18 Sheared off spherical tip 16 Figure 19 Centrally relieved flat skid 16 Figure 20 Skid errors 17 Figure 21 Profiles traced by a spherical skid on a sinusoidal specimen 17 Fi
10、gure 22 Effect of oblique traversing on wavelength 20 Table 1 Nominal values of depth and width for type A1 3 Table 2 Tolerances for types A1 and A2 3 Table 3 Nominal values of depth and radius for type A2 4 Table 4 Tolerances for type B2 sensitive and insensitive grids 5 Table 5 Nominal values of R
11、 afor type C1 5 Table 6 Tolerances for types C1 to C4 5 Table 7 Nominal values of R aand for type C2 6 Table 8 Nominal unfiltered values of R afor type C4 7 Table 9 Tolerances for type D 7 Table 10 Values of k 19 Table 11 Skid radii giving5% maximum out-of-phase error 19 Publications referred to Ins
12、ide back coverBS6393:1987 ii BSI 07-1999 National foreword This British Standard, which has been prepared under the direction of the General Mechanical Engineering Standards Committee, is identical with ISO5436:1985 “Calibration specimens Stylus instruments Types, calibration and use of specimens”,
13、published by the International Organization for Standardization (ISO). This British Standard is a revision ofBS6393:1983, which is withdrawn. Terminology and conventions. The text of the international standard has been approved as suitable for publication as a British Standard without deviation. Som
14、e terminology and certain conventions are not identical with those used in British Standards; attention is drawn especially to the following. The comma has been used as a decimal marker. In British Standards it is current practice to use a full point on the baseline as the decimal marker. Wherever t
15、he words “International Standard” appear, referring to this standard, they should be read as “British Standard”. Cross-references. The Technical Committee has reviewed the provisions ofISO468,ISO1878,ISO1879,ISO1880 andISO3274, to which reference is made in the text, and has decided that they are ac
16、ceptable for use in conjunction with this standard. NOTE 1In B.3.5, paragraph 2, line 2, “grooves” should be read as “groove”. NOTE 2In B.4, paragraph 6, line 3, “values” should be read as “value”. A British Standard does not purport to include all the necessary provisions of a contract. Users of Br
17、itish Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 22, an inside back cover and a back co
18、ver. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS6393:1987 BSI 07-1999 1 1 Scope and field of application This International Standard specifies the characteristics of specimens
19、 for the calibration of stylus instruments (seeISO1880 andISO3274) and the annexes give information regarding their calibration and application to the calibration and adjustment in laboratories, standards rooms and workshops. 2 References ISO 468, Surface roughness Parameters, their values and gener
20、al rules for specifying requirements. ISO 1878, Classification of instruments and devices for measurement and evaluation of the geometrical parameters of surface finish. ISO 1879, Instruments for the measurement of surface roughness by the profile method Vocabulary. ISO 1880, Instruments for the mea
21、surement of surface roughness by the profile method Contact (stylus) instruments of progressive profile transformation Profile recording instruments. ISO 3274, Instruments for the measurement of surface roughness by the profile method Contact (stylus) instruments of consecutive profile transformatio
22、n Contact profile meters, system M. 3 Definitions For the purposes of this International Standard, the definitions given inISO468,ISO1878,ISO1879 andISO3274, and the following apply. standard instrument calibration specimen a specimen having accurately determined standardized characteristics for tes
23、ting or establishing one or more features of the performance of an instrument 4 Types and purposes of instrument calibration specimens The calibration of the existing wide range of instruments in all modes of operation calls for more than one type of calibration specimen. Each calibrated specimen ma
24、y have a limited range of application according to its own characteristics and those of the instrument to be calibrated. The validity of the calibration of an instrument will be dependent on the correct association of these characteristics. To cover the range of requirements, four types of specimens
25、 are described, each of which may have a number of variants. Their principal applications are specified in 4.1 to 4.4 and dimensions and tolerances in 7.1 to 7.4. 4.1 Type A These specimens are for checking the vertical magnification of profile recording instruments having displacement sensitive pic
26、k-ups. 4.1.1 Type A1 These specimens have a wide calibrated groove with a flat bottom, or a number of separated grooves of equal or increasing depth, each groove being wide enough to be insensitive to the shape or condition of the stylus tip. 4.1.2 Type A2 These specimens are similar to type A1, exc
27、ept that the grooves have rounded bottoms of sufficient radius to be insensitive to the shape or condition of the stylus tip. 4.2 Type B These specimens are primarily for checking the condition of the stylus tip. 4.2.1 Type B1 These specimens have a narrow groove or a number of separated grooves pro
28、portioned to be increasingly sensitive to the dimensions of the stylus. They are intended for use with instruments having displacement sensitive pick-ups.BS6393:1987 2 BSI 07-1999 4.2.2 Type B2 These specimens have two grids of nominally equal R avalues, one being sensitive and the other insensitive
29、 to the dimensions of the stylus tip. These grids are used comparatively for checking the stylus tips of parameter instruments having motion-sensitive pick-ups, the ratio of the R avalues being taken as the criterion. 4.3 Type C These specimens are primarily intended for checking parameter meters. T
30、hey have a grid of repetitive grooves of simple shape (either sinusoidal, triangular or arcuate) which have relatively low harmonic amplitudes. They are used primarily for calibrating parameter meters, but they may also be used for checking horizontal magnification if the spacing of the grooves is h
31、eld within limits acceptable for this purpose. An essential requirement of type C calibration specimens is that standardized specimens of differing waveform are nevertheless compatible, in the sense that they will all lead to the same state of instrument calibration or verification, provided they ar
32、e used correctly. The declared parameter values issued with each specimen refer to a smooth straight datum and filtered profiles derived from the trace according toISO3274. Although the wider grooves are generally insensitive to the dimensions of the stylus tip, sensitivity in this respect may becom
33、e appreciable for the narrowest grooves; and for this reason the parameter values shall be declared with reference to the stylus tip. 4.3.1 Use for skidless instruments Each specimen will calibrate a skidless instrument (one which traces the profile with respect to a smooth straight datum) with resp
34、ect to the particular crest spacing of that specimen. The purpose of the series of specimens is to enable the transmission characteristic to be checked for a number of spacings and amplitudes. 4.3.2 Use for skid-type instruments The use of type C specimens for calibrating skid-type instruments is re
35、stricted to those for which the generally indeterminate rise and fall of the skid(s) over the crests makes an insignificant contribution to the calibration. This is best assured by using a specimen having the shortest crest spacing permitted by the stylus, as shown in Annex B, and this is the genera
36、l practice. 4.4 Type D These specimens are for overall check of meter calibration. They have irregular profiles (for example as obtained by grinding) in the direction of traverse, but they have the convenience of an approximately constant cross-section along their lengths. The specimens simulate wor
37、kpieces containing a wide range of crest spacings, but reduce the number of traverses needed to give a good average value. They provide, for reassurance, a final overall check on calibration. The accuracy obtainable by averaging a few random traverses will generally be less than type C specimens, bu
38、t may be sufficient for workshop purposes. Higher accuracy can be obtained by averaging a statistically determined number of appropriately positioned traverses. 1) 5 Materials The material used shall be hard enough to ensure adequate life in relation to cost. Its surface shall be smooth and flat eno
39、ugh not to affect the evaluation of the grooves. Glass or quartz or materials harder than750HV are favoured. 6 Size of specimen The operative area shall be large enough to provide for the total length of traverse required for all intended determinations. One or more than one kind of specimen may be
40、provided on a single block. So as to ensure the best possible economic conditions, overall dimensions of specimens are not given. 1) To form the subject of a future International Standard.BS6393:1987 BSI 07-1999 3 7 Mechanical requirements It should be noted that, in the tables which follow, the nom
41、inal values carry a wide tolerance, and that these values should not be used as the basis of instrument calibration (see clause 9, notes 1 and 2). 7.1 Type A 7.1.1 Type A1: Wide grooves with flat bottoms (see Figure 1 and Table 1) Table 1 Nominal values of depth and width for type A1 If a skid is us
42、ed, it shall not cross a groove at the same time that the stylus crosses the groove being measured. For tolerances, see Table 2. Table 2 Tolerances for types A1 and A2 7.1.2 Type A2: Wide grooves with rounded bottoms (see Figure 2 and Table 3) Figure 1 Type A1 groove Values in micrometres Depth, d 0
43、,3 1,0 3,0 10 30 100 Width, w 100 100 200 200 500 500 Nominal value Tolerance on nominal value Uncertainty of measurement in calibrated mean depth Standard deviation from the calibrated mean 4m % % (4m) % 0,3 1 3 10 30 100 20 15 10 10 10 10 3 2 2 2 2 2 ( 0,01) ( 0,02) ( 0,06) ( 0,2) ( 0,6) ( 2) 3 2
44、2 2 2 2 Figure 2 Type A2 grooveBS6393:1987 4 BSI 07-1999 Table 3 Nominal values of depth and radius for type A2 If a skid is used, it shall not cross the groove at the same time that the stylus crosses the groove being measured. For tolerances, see Table 2. 7.1.3 The basis of assessment for types A1
45、 and A2 is given in 8.1; requirements regarding statements of mean values are given in clause 9; guidance on calibration is given in clauses A.1 and A.2; guidance on use is given in clauses B.1 and B.2. 7.2 Type B grooves for checking stylus tips 7.2.1 Type B1 Development of specimens having single
46、narrow grooves is proceeding, but is not yet sufficiently advanced to permit standardization. 7.2.2 Type B2 These specimens have two grids formed on a common base. 7.2.2.1 Sensitive grid (see Figure 3) Isosceles triangular grooves with sharp peaks and valleys, for testing 104m radius tips. For104m r
47、adius tips: = 150 R a= 0,5 4m 5% S mshall be determined by and R a , and will thus have the mid-limit value of154m. For tolerances, see Table 4. 7.2.2.2 Insensitive grid (see Figure 4) Sinusoidal or arcuate grooves, proportioned to make R asubstantially independent of the stylus tip. For104m radius
48、tips: R a=0,54m 5% Depth, d, (4m) 1,0 3,0 10 30 100 Radius, r, (mm) 1,5 1,5 1,5 0,75 0,75 Figure 3 Type B2 grooves (sensitive grid) Figure 4 Type B2 grooves (insensitive grid)BS6393:1987 BSI 07-1999 5 S m=0,25mm For tolerances, see Table 4. NOTE 1Grooves for tips with a radius of less than104m (if s
49、uch are practical) have still to be developed. NOTE 2For convenience, one or more type C grids may be added for general calibration of R a . Such grids shall be clearly. distinguished from the type B2 pair. 7.2.3 The basis of assessment for typeB2is given in 8.2, tolerances are given in 7.2.2 and Table 4, and the method of use is described inB.4. Table 4 Tolerances for type B2 sensitive and insensitive grids 7.3 Type C The nom
