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1、DD CEN ISO/TS 12781-2:2007 ICS 01.040.17; 17.040.01 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW DRAFT FOR DEVELOPMENT Geometrical Product Specifications (GPS) Flatness Part 2: Specification operators (ISO/TS 12781-2:2003) Licensed CopyChinese University of Hong Kong, 21/10
2、/2008 04:34, Uncontrolled Copy, (c) BSI This Draft for Development was published under the authority of the Standards Policy and Strategy Committee on 31 August 2008 BSI 2008 ISBN 978 0 580 57993 6 Amendments/corrigenda issued since publication DateComments DD CEN ISO/TS 12781-2:2007 National forewo
3、rd This Draft for Development is the UK implementation of CEN ISO/TS 12781-2:2007. It is identical to ISO/TS 12781-2:2003. This publication is not to be regarded as a British Standard. It is being issued in the Draft for Development series of publications and is of a provisional nature. It should be
4、 applied on this provisional basis, so that information and experience of its practical application can be obtained. Comments arising from the use of this Draft for Development are requested so that UK experience can be reported to the international organization responsible for its conversion to an
5、international standard. A review of this publication will be initiated not later than 3 years after its publication by the international organization so that a decision can be taken on its status. Notification of the start of the review period will be made in an announcement in the appropriate issue
6、 of Update Standards. According to the replies received by the end of the review period, the responsible BSI Committee will decide whether to support the conversion into an international Standard, to extend the life of the Technical Specification or to withdraw it. Comments should be sent to the Sec
7、retary of the responsible BSI Technical Committee at British Standards House, 389 Chiswick High Road, London W4 4AL. The UK participation in its preparation was entrusted to Technical Committee TDW/4, Technical product realization (TPR). A list of organizations represented on this committee can be o
8、btained 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. Compliance with a British Standard cannot confer immunity from legal obligations. Licensed CopyChinese University of Hong K
9、ong, 21/10/2008 04:34, Uncontrolled Copy, (c) BSI DD CEN ISO/TS 12781-2:2007DD CEN ISO/TS 12781-2:2007 TECHNICAL SPECIFICATION SPCIFICATION TECHNIQUE TECHNISCHE SPEZIFIKATION CEN ISO/TS 12781-2 December 2007 ICS 17.040.01; 01.040.17 English Version Geometrical product specifications (GPS) - Flatness
10、 - Part 2: Specification operators (ISO/TS 12781-2:2003) Spcification gomtrique des produits (GPS) - Planit - Partie 2: Oprateurs de spcification (ISO/TS 12781- 2:2003) Geometrische Produktspezifikation (GPS) - Ebenheit - Teil 2: Spezifikationsoperatoren (ISO/TS 12781-2:2003) This Technical Specific
11、ation (CEN/TS) was approved by CEN on 8 October 2007 for provisional application. The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their comments, particularly on the question whether the CEN/TS can be converted
12、 into a European Standard. CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS)
13、until the final decision about the possible conversion of the CEN/TS into an EN is reached. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Lu
14、xembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2007 CENAll
15、rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. CEN ISO/TS 12781-2:2007: E Licensed CopyChinese University of Hong Kong, 21/10/2008 04:34, Uncontrolled Copy, (c) BSI DD CEN ISO/TS 12781-2:2007DD CEN ISO/TS 12781-2:2007 CEN ISO/TS 12781-2:2007
16、 (E) 2 Contents Page Foreword3 Licensed CopyChinese University of Hong Kong, 21/10/2008 04:34, Uncontrolled Copy, (c) BSI DD CEN ISO/TS 12781-2:2007DD CEN ISO/TS 12781-2:2007 CEN ISO/TS 12781-2:2007 (E) 3 Foreword The text of ISO/TS 12781-2:2003 has been prepared by Technical Committee ISO/TC 213 “D
17、imensional and geometrical product specifications and verification” of the International Organization for Standardization (ISO) and has been taken over as CEN ISO/TS 12781-2:2007 by Technical Committee CEN/TC 290 “Dimensional and geometrical product specification and verification” the secretariat of
18、 which is held by AFNOR. Attention 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. According to the CEN/CENELEC Internal Regulations, the nation
19、al standards organizations of the following countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norwa
20、y, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO/TS 12781-2:2003 has been approved by CEN as a CEN ISO/TS 12781-2:2007 without any modification. Licensed CopyChinese University of Hong Kong, 21/10/2008 04:34, Unco
21、ntrolled Copy, (c) BSI DD CEN ISO/TS 12781-2:2007DD CEN ISO/TS 12781-2:2007 ISO/TS 12781-2:2003(E) ISO 2003 All rights reserved v Introduction This part of ISO/TS 12781 is a geometrical product specification (GPS) Technical Specification and is to be regarded as a general GPS document (see ISO/TR 14
22、638). It influences chain link 3 of the chain of standards on form of a surface (independent of a datum). For more detailed information on the relation of this part of ISO/TS 12781 to other standards and the GPS matrix model, see Annex C. This part of ISO/TS 12781 specifies the specification operato
23、rs according to ISO/TS 17450-2 for flatness of integral features. At the current state of development, ISO TC 213 has not been able to reach a consensus on defaults for filter UPR, probe tip radius and method of association (reference plane). This means that a flatness specification must explicitly
24、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 uncertain (see ISO/TS 17450-2) and a supplier can use any
25、 value for the operator(s) not specified when proving conformance. Extracting data will always involve applying a certain filtering process. An additional filtering of the extracted data may or may not be applied. This additional filter can be a mean line filter (Gaussian, spline, wavelet, etc.) or
26、a non-linear filter (e.g. morphological filter). The type of filtering will influence 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 profile. In certain circumstances it can
27、 create spurious high-frequency content, thus giving incorrect values. To correct this, a longwave-pass filter is employed. A Gaussian filter is used, since this is the current state-of-the-art in ISO standards. This filter has some shortcomings, e.g. it can distort, rather than eliminate some rough
28、ness features and it can distort, rather than transmit correctly some waviness features. It is envisioned that new filters under development within ISO will 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,
29、 the resulting measured value will generally be higher. This effect is usually insignificant. If a larger tip radius is used, the resulting measured value will generally be lower. The amount of change is heavily dependent on the surface measured. NOTE 3 The measuring force of 0 N is chosen to elimin
30、ate effects of elastic deformation of the workpiece from the specification operator. On metal surfaces with adequate thickness, the effect of normally occurring measuring forces will be negligible. NOTE 4 Aliasing and other problems during extraction (see Annex A) due to the higher harmonic content
31、of the skin model, in the straightness directions, can cause specification uncertainty. This part of ISO/TS 12781 is not intended to disallow any means of measuring flatness. Licensed CopyChinese University of Hong Kong, 21/10/2008 04:34, Uncontrolled Copy, (c) BSI DD CEN ISO/TS 12781-2:2007DD CEN I
32、SO/TS 12781-2:2007 Licensed CopyChinese University of Hong Kong, 21/10/2008 04:34, Uncontrolled Copy, (c) BSI DD CEN ISO/TS 12781-2:2007DD CEN ISO/TS 12781-2:2007 TECHNICAL SPECIFICATION ISO/TS 12781-2:2003(E) ISO 2003 All rights reserved 1 Geometrical Product Specifications (GPS) Flatness Part 2: S
33、pecification operators 1 Scope This part of ISO/TS 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 following referenced documents are indispensable f
34、or 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/TS 12781-1:2003, Geometrical Product Specifications (GPS) Flatness Part 1: Vocabulary and parameter
35、s 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/TS 17450-2:2002, Geometrical Product Specifications (GPS) General concept
36、s Part 2: Basic temets, specifications, operators and uncertainties 3 Terms and definitions For the purposes of this part of ISO/TS 12781, the terms and definitions given in ISO/TS 12781-1 and ISO/TS 17450-2 apply. 4 Complete specification operator 4.1 General The complete specification operator (se
37、e ISO/TS 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 achieve compreh
38、ensive 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 the deviations fro
39、m flat form. Licensed CopyChinese University of Hong Kong, 21/10/2008 04:34, Uncontrolled Copy, (c) BSI DD CEN ISO/TS 12781-2:2007DD CEN ISO/TS 12781-2:2007 ISO/TS 12781-2:2003(E) 2 ISO 2003 All rights reserved 4.2 Probing system 4.2.1 Probing method A contacting probing system with a stylus tip as
40、defined in 4.2.2 is part of the specification operator. 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 specification For proving conformance or non-conformance with specification, ISO 14253-1 applies.
41、 Licensed CopyChinese University of Hong Kong, 21/10/2008 04:34, Uncontrolled Copy, (c) BSI DD CEN ISO/TS 12781-2:2007DD CEN ISO/TS 12781-2:2007 ISO/TS 12781-2:2003(E) ISO 2003 All rights reserved 3 Annex A (informative) Harmonic content of a nominally flat workpiece and extraction strategy A.1 Harm
42、onic 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 whose wavelength is the length of the signal and harmonic sinusoids whose wavelengths divide into the fundamental wavelength a who
43、le 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 second harmonic. The sinusoid whose wavelength is one-third the fundamental wavelength is called the third harmonic, etc. (see Figur
44、e A.1). Thus the nth harmonic is that sinusoid whose wavelength divides into the fundamental wavelength exactly n times. a) 1st harmonic b) 2nd harmonic c) 3rd harmonic Figure A.1 First three harmonics of a signal All of the above signals decomposed into Fourier series are profiles, whereas the surf
45、ace 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 coordinate 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
46、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 origin. Licensed CopyChinese University of Hong Kong, 21/10/2008 04:34, Uncontrolled Copy, (c) BSI DD CEN ISO/TS 12781-2:2007DD CEN ISO/TS 1
47、2781-2:2007 ISO/TS 12781-2:2003(E) 4 ISO 2003 All rights reserved In a similar way an area can be decomposed into the combination of two Fourier series. In practice, this area will have a finite length in each of the two directions defined by the orthogonal profiles. Each individual component of thi
48、s decomposition has two harmonic numbers; the first corresponds to the number of the harmonic in the direction 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 harmon
49、ic 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 waves along the other profile length). It is important to consider which of these harmonics are present on a feature of flatness when specifying an appropriate sampling strategy for assessment. A.2 Aliasing and the Nyquist criterion Recording digital data from a signal involves sampling that signal. The separation of the
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