1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN ISO 12780-2:2011Geometrical pr o d u c t specifications (GPS) StraightnessPart 2: Specification operatorsBS EN ISO 12780-2:2011 BRITISH STANDARDNational forewordThis Britis
2、h Standard is the UK implementation of EN ISO 12780-2:2011. It supersedes DD CEN ISO/TS 12780-2:2007, which is withdrawn.The UK participation in its preparation was entrusted to T e c h n i c a l C o m m i t t e e T D W / 4 , T e c h n i c a l P r o d u c t R e a l i z a t i o n .A list of organizat
3、ions represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. BSI 2011 ISBN 978 0 580 66725 1 ICS 17.040.20 Compliance with a British Standard
4、cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 April 2011.Amendments issued since publicationDate T e x t a f f e c t e dEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 12780-2 April
5、2011 ICS 17.040.01 Supersedes CEN ISO/TS 12780-2:2007English Version Geometrical product specifications (GPS) - Straightness - Part 2: Specification operators (ISO 12780-2:2011) Spcification gomtrique des produits (GPS) - Rectitude -Partie 2: Oprateurs de spcification (ISO 12780-2:2011) Geometrische
6、 Produktspezifikation (GPS) - Geradheit - Teil 2: Spezifikationsoperatoren (ISO 12780-2:2011) This European Standard was approved by CEN on 17 March 2011. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the st
7、atus of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French,
8、German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cro
9、atia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARD
10、IZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 12780-2:2011: EBS EN ISO 12780-2:2011 EN ISO 12780-
11、2:2011 (E) 3 Foreword This document (EN ISO 12780-2:2011) has been prepared by Technical Committee ISO/TC 213 “Dimensional and geometrical product specifications and verification“ in collaboration with Technical Committee CEN/TC 290 “Dimensional and geometrical product specification and verification
12、” the secretariat of which is held by AFNOR. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by October 2011, and conflicting national standards shall be withdrawn at the latest by October 2011. Atte
13、ntion is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes CEN ISO/TS 12780-2:2007. According to the CEN/CENELEC Internal Re
14、gulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg,
15、Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 12780-2:2011 has been approved by CEN as a EN ISO 12780-2:2011 without any modification. BS EN ISO 12780-2:2011ISO 12780-2:2011(E) ISO 2011
16、 All rights reserved iiiContents Page Foreword iv Introduction.v 1 Scope1 2 Normative references1 3 Terms and definitions .1 4 Complete specification operator .1 4.1 General .1 4.2 Transmission band2 4.3 Probing system3 5 Compliance with specification.3 Annex A (informative) Harmonic content of a no
17、minally straight workpiece.4 Annex B (informative) Relationship to the GPS matrix model .6 Bibliography8 BS EN ISO 12780-2:2011ISO 12780-2:2011(E) iv ISO 2011 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (
18、ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, go
19、vernmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IE
20、C Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the memb
21、er bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 12780-2 was prepared by Technical Committee ISO/TC 213, Dimensional and
22、 geometrical product specifications and verification. This first edition of ISO 12780-2 cancels and replaces ISO/TS 12780-2:2003, which has been technically revised. ISO 12780 consists of the following parts, under the general title Geometrical product specifications (GPS) Straightness: Part 1: Voca
23、bulary and parameters of straightness Part 2: Specification operators BS EN ISO 12780-2:2011ISO 12780-2:2011(E) ISO 2011 All rights reserved vIntroduction This part of ISO 12780 is a geometrical product specification (GPS) standard and is to be regarded as a general GPS standard (see ISO/TR 14638).
24、It influences chain link 3 of the chain of standards on form of line independent of datum. The ISO/GPS Masterplan given in ISO/TR 14638 gives an overview of the ISO/GPS system of which this document is a part. The fundamental rules of ISO/GPS given in ISO 8015 apply to this document and the default
25、decision rules given in ISO 14253-1 apply to specifications made in accordance with this document, unless otherwise indicated. For more detailed information on the relationship of this part of ISO 12780 to other standards and the GPS matrix model, see Annex B. This part of ISO 12780 specifies the sp
26、ecification operators according to ISO 17450-2 for straightness of integral features. This part of ISO 12780 does not specify defaults for filter cut-off, probe tip radius and method of association (reference line). This means that it is necessary for a straightness specification to explicitly state
27、 which values are to be used for these specification operations in order for it to be unique. Consequently, if a specification does not explicitly state which values are to be used for one or more of these operators, the specification is ambiguous (see ISO 17450-2) and a supplier can use any value f
28、or the operator(s) not specified when proving conformance. Extracting data always involves applying a certain filtering process. An additional filtering of the extracted data might or might not be applied. This additional filter can be a mean line filter (Gaussian, spline, wavelet, etc.) or a non-li
29、near filter (e.g. morphological filter). The type of filtering influences the definition of straightness and the specification operators and, therefore, needs to be stated unambiguously. NOTE 1 Stylus filtering is not sufficient on its own to smooth a profile. In certain circumstances, it can create
30、 spurious high-frequency content, thus giving incorrect values. To correct this, a longwave-pass filter can be employed. A Gaussian filter is used, since this is the state-of-the-art. This filter has some shortcomings, e.g. it can distort rather than eliminate some roughness features and it can dist
31、ort rather than transmit correctly some waviness features. It is envisioned that new filters under development within ISO provide better solutions for several of these issues. NOTE 2 If a smaller tip radius than the one specified is used for a given cut-off length, the resulting measured value is ge
32、nerally higher. This effect is usually insignificant. If a larger tip radius is used, the resulting measured value is generally lower. The amount of change is heavily dependent on the surface measured. NOTE 3 The measuring force of 0 N is chosen to eliminate effects of elastic deformation of the wor
33、kpiece from the specification operator. On metal surfaces with adequate thickness, the effect of normally occurring measuring forces is negligible. NOTE 4 Aliasing and other problems during extraction (see Annex A), due to the higher harmonic content of the skin model, in the straightness directions
34、, can cause specification uncertainty. This part of ISO 12780 is not intended to disallow any means of measuring straightness. BS EN ISO 12780-2:2011BS EN ISO 12780-2:2011INTERNATIONAL STANDARD ISO 12780-2:2011(E) ISO 2011 All rights reserved 1Geometrical product specifications (GPS) Straightness Pa
35、rt 2: Specification operators 1 Scope This part of ISO 12780 specifies the complete specification operator for straightness of integral features only and covers complete straightness profiles only, i.e. geometrical characteristics of features of type line. NOTE Straightness of an extracted median li
36、ne of a cylinder is defined in ISO 12180-1. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any ame
37、ndments) applies. ISO 11562:1996, Geometrical Product Specifications (GPS) Surface texture: Profile method Metrological characteristics of phase correct filters ISO 12780-1:2011, Geometrical product specifications (GPS) Straightness Part 1: Vocabulary and parameters of straightness ISO 14253-1:1998,
38、 Geometrical Product Specifications (GPS) Inspection by measurement of workpieces and measuring equipment Part 1: Decision rules for proving conformance or non-conformance with specifications ISO 17450-2:1), Geometrical product specifications (GPS) General concepts Part 2: Basic tenets, specificatio
39、ns, operators and uncertainties 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 12780-1 and ISO 17450-2 apply. 4 Complete specification operator 4.1 General The complete specification operator (see ISO 17450-2) is a full ordered set of unambiguous sp
40、ecification operations in a well-defined order. The complete specification operator defines the transmission band for the straightness profile, together with an appropriate stylus tip geometry. 1) To be published. (Revision of ISO/TS 17450-2:2002) BS EN ISO 12780-2:2011ISO 12780-2:2011(E) 2 ISO 2011
41、 All rights reserved4.2 Transmission band 4.2.1 Longwave-pass filter The longwave-pass filter shall be a phase correct filter (according to ISO 11562) transmitting waves of infinite length and attenuating profile undulations progressively in the undulation region around the cut-off length (see Figur
42、e 1). Key X wavelength, in millimetres Y transmission, as a percentage NOTE Other filter values than those shown in this figure can be used, if necessary for the application. Figure 1 Transmission characteristic for longwave-pass filter having cut-off lengths c= 0,08 mm; 0,25 mm; 0,8 mm; 2,5 mm; 8 m
43、m The attenuation function is given by: 2c10aea= where ()ln 20,469 7 =a0is the amplitude of sine wave undulation before filtering; a1is the amplitude of this sine wave undulation after filtering; cis the cut-off length of the longwave-pass filter; is the wavelength of the sine wave. BS EN ISO 12780-
44、2:2011ISO 12780-2:2011(E) ISO 2011 All rights reserved 34.2.2 Cut-off wavelengths The profile filter determines the range of periodic sinusoidal undulations of the feature included in the straightness assessment. The range is terminated by values taken from Table 1. Table 1 also gives the maximum sa
45、mple point spacing that shall be used for the extracted line and the stylus tip radius needed to avoid distortion of the straightness profile from the influence of the stylus tip. Table 1 Cut-off values Dimensions in millimetresLongwave-pass filters Filter transmitting from infinite wavelength down
46、to Maximum sample point spacingMaximum stylus tip radiusaR 8 1,14 5 2,5 0,357 1,5 0,8 0,114 0,5 0,25 0,035 7 0,15 0,08 0,011 4 0,05 aWhen the maximum stylus tip radius requirement is fulfilled, the radius of the stylus tip is of comparable size to the wavelength of the shortest undulations transmitt
47、ed by the profile filter. This is consistent with the stylus tip radius requirements for surface texture measuring instruments (see ISO 3274). NOTE 1 The required number of points corresponds to seven sample points for each cut-off, which is the minimum number of points to be assessed. NOTE 2 If a l
48、onger or shorter cut-off value than those given in Table 1 is used, then the applicable maximum sample point spacing and maximum stylus tip radius can be calculated from the ratios in Table 1. 4.3 Probing system 4.3.1 Probing method A contacting probing system with a stylus tip, as defined in 4.3.2,
49、 is part of the specification operator. 4.3.2 Stylus tip geometry The theoretically exact stylus tip geometry is a sphere. 4.3.3 Probing force The probing force is 0 N. 5 Compliance with specification For proving conformance or non-conformance with specification, ISO 14253-1 applies. BS EN ISO 12780-2:2011ISO 12780-2:2011(E) 4 ISO 2011 All rights reservedAnnex A (informative) Harmonic content of a nominally straight workpiece A.1 Harmonic content A finite length signal can be decomposed into a numbe
