1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN ISO 12781-2:2011Geometrical pr o d u c t specifications (GPS) FlatnessPart 2: Specification operatorsBS EN ISO 12781-2:2011 BRITISH STANDARDNational forewordThis British St
2、andard is the UK implementation of EN ISO 12781-2:2011. It supersedes DD CEN ISO/TS 12781-2:2007, which is withdrawn.The UK participation in its preparation was entrusted to T e c h n i c a l C o m m i t t e e T D W / 4 , T e c h n i c a l P r o d u c t R e a l i z a t i o n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 organizations
3、 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 66727 5 ICS 17.040.20 Compliance with a British Standard cann
4、ot 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 12781-2 April 2011
5、 ICS 17.040.20 Supersedes CEN ISO/TS 12781-2:2007English Version Geometrical product specifications (GPS) - Flatness - Part 2: Specification operators (ISO 12781-2:2011) Spcification gomtrique des produits (GPS) - Planit - Partie 2: Oprateurs de spcification (ISO 12781-2:2011) Geometrische Produktsp
6、ezifikation (GPS) - Ebenheit - Teil 2: Spezifikationsoperatoren (ISO 12781-2:2011) This European Standard was approved by CEN on 26 February 2011. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of
7、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, German).
8、 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, Croatia, Cy
9、prus, 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 STANDARDIZATION
10、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 12781-2:2011: EBS EN ISO 12781-2:2011 EN ISO 12781-2:2011 (
11、E) 3 Foreword This document (EN ISO 12781-2:2011) 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” the se
12、cretariat 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. Attention is
13、 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 12781-2:2007. According to the CEN/CENELEC Internal Regulation
14、s, 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, Malta, N
15、etherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 12781-2:2011 has been approved by CEN as a EN ISO 12781-2:2011 without any modification. BS EN ISO 12781-2:2011ISO 12781-2:2011(E) ISO 2011 All rig
16、hts 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 Probing system2 5 Compliance with the specification 2 Annex A (informative) Harmonic content of a nominally flat workpiece and
17、extraction strategy3 Annex B (informative) Extraction strategies 7 Annex C (informative) Relationship to the GPS matrix model .11 Bibliography13 BS EN ISO 12781-2:2011ISO 12781-2:2011(E) iv ISO 2011 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide f
18、ederation of national standards bodies (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 co
19、mmittee. International organizations, governmental 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 accor
20、dance with the rules given in the ISO/IEC 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 requir
21、es approval by at least 75 % of the member 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 12781-2 was prepared by Technic
22、al Committee ISO/TC 213, Dimensional and geometrical product specifications and verification. This first edition of ISO 12781-2 cancels and replaces ISO/TS 12781-2:2003, which has been technically revised. ISO 12781 consists of the following parts, under the general title Geometrical product specifi
23、cations (GPS) Flatness: Part 1: Vocabulary and parameters of flatness Part 2: Specification operators BS EN ISO 12781-2:2011ISO 12781-2:2011(E) ISO 2011 All rights reserved vIntroduction This part of ISO 12781 is a geometrical product specification (GPS) standard and is to be regarded as a general G
24、PS standard (see ISO/TR 14638). It influences chain link 3 of the chain of standards on form of a surface (independent of a datum). The ISO/GPS Masterplan given in ISO/TR 14638 gives an overview of the ISO/GPS system of which this part of ISO 12781 is a part. The fundamental rules of ISO/GPS given i
25、n ISO 8015 apply to this part of ISO 12781 and the default decision rules given in ISO 14253-1 apply to specifications made in accordance with this part of ISO 12781, unless otherwise indicated. For more detailed information on the relationship of this part of ISO 12781 to other standards and the GP
26、S matrix model, see Annex C. This part of ISO 12781 specifies the specification operators according to ISO 17450-2 for flatness of integral features. ISO 12780-2 does not specify defaults for filter cut-off, probe tip radius and method of association (reference plane). This means that it is necessar
27、y for a flatness specification to explicitly state 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 (s
28、ee ISO 17450-2) and a supplier can use any value for 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 fi
29、lter (Gaussian, spline, wavelet, etc.) or a non-linear filter (e.g. morphological filter). The type of filtering influences the definition of flatness and the specification operators and, therefore, needs to be stated unambiguously. NOTE 1 Stylus filtering is not sufficient on its own to smooth a pr
30、ofile. In certain circumstances, it can create 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 el
31、iminate some roughness features and it can distort, 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 cu
32、t-off length, the resulting measured value is generally 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 eli
33、minate effects of elastic deformation of the workpiece 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
34、 the skin model, in the straightness directions, can cause specification uncertainty. This part of ISO 12781 is not intended to disallow any means of measuring flatness. BS EN ISO 12781-2:2011BS EN ISO 12781-2:2011INTERNATIONAL STANDARD ISO 12781-2:2011(E) ISO 2011 All rights reserved 1Geometrical p
35、roduct specifications (GPS) Flatness Part 2: Specification operators 1 Scope This part of ISO 12781 specifies the complete specification operator for flatness of complete integral features only, i.e. geometrical characteristics of individual features of type plane. 2 Normative references The followi
36、ng 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 amendments) applies. ISO 12781-1:2011, Geometrical product specifications (GPS) F
37、latness Part 1: Vocabulary and parameters of flatness ISO 14253-1:1998, 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 s
38、pecifications (GPS) General concepts Part 2: Basic temets, specifications, operators and uncertainties 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 12781-1 and ISO 17450-2 apply. 4 Complete specification operator 4.1 General The complete specifica
39、tion operator (see ISO 17450-2) is a full ordered set of unambiguous specification operations in a well-defined order. The complete specification operator defines the transmission band for the flatness surface, together with an appropriate stylus tip geometry. NOTE In practice, it is unrealistic to
40、achieve comprehensive coverage of the flatness feature given by the theoretical minimum density of points (see Annex B) within an acceptable time span using current technology. Therefore, more limited extraction strategies are employed that give specific rather than general information concerning th
41、e deviations from flat form. 1) To be published. (Revision of ISO/TS 17450-2:2002) BS EN ISO 12781-2:2011ISO 12781-2:2011(E) 2 ISO 2011 All rights reserved4.2 Probing system 4.2.1 Probing method A contacting probing system with a stylus tip, as defined in 4.2.2, is part of the specification operator
42、. 4.2.2 Stylus tip geometry The theoretically exact stylus tip geometry is a sphere. 4.2.3 Probing force The probing force is 0 N. 5 Compliance with the specification For proving conformance or non-conformance with the specification, ISO 14253-1 applies. BS EN ISO 12781-2:2011ISO 12781-2:2011(E) ISO
43、 2011 All rights reserved 3Annex A (informative) Harmonic content of a nominally flat workpiece and extraction strategy A.1 Harmonic content A finite length signal can be decomposed into a number of sinusoidal components called a Fourier series. A Fourier series consists of a fundamental sinusoid wh
44、ose wavelength is the length of the signal and harmonic sinusoids, whose wavelengths divide into the fundamental wavelength a whole number of times. The fundamental sinusoid is called the first harmonic of the signal. The sinusoid whose wavelength is half the fundamental wavelength is called the sec
45、ond harmonic. The sinusoid whose wavelength is one third the fundamental wavelength is called the third harmonic, etc. (see Figure A.1). Thus, the nth harmonic is that sinusoid whose wavelength divides into the fundamental wavelength exactly n times. a) First harmonic b) Second harmonic c) Third har
46、monic Figure A.1 First three harmonics of a signal All of the above signals decomposed into Fourier series are profiles, whereas the surface of a plane is an area. An area can be thought of as the combination of two profiles where the directions of the two profiles can be used to establish a coordin
47、ate system for the area. In the case of a plane, the two profiles are orthogonal to each other within the plane, with any position on the plane being located by giving its coordinates with respect to its distance in the direction of one profile and distance in the other profiles direction from an or
48、igin. In a similar way, an area can be decomposed into a combination of two Fourier series. In practice, this area has a finite length in each of the two directions defined by the orthogonal profiles. Each individual component of this decomposition has two harmonic numbers; the first corresponds to
49、the number of the harmonic in the BS EN ISO 12781-2:2011ISO 12781-2:2011(E) 4 ISO 2011 All rights reserveddirection of the first profile and the second number corresponds to the harmonic number in the direction of the second profile. The individual component is a combination of these two specified harmonic components. For example the (6,4) harmonic consists of a term that is a combination of the sixth harmonic of the first profile (i.e. 6 waves across its length) and the fourth harmonic on the other profile (i.e. 4 wa
