1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 2971:2013Cigarettes and filter rods Determination of nominaldiameter Method using anon-contact optical measuringapparatusBS ISO 2971:2013 BRITISH STANDARDNational foreword
2、This British Standard is the UK implementation of ISO 2971:2013. Itsupersedes BS 5381-2:1998 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee AW/40, Tobacco and tobacco products.A list of organizations represented on this committee can beobtained on requ
3、est to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2013. Published by BSI StandardsLimited 2013ISBN 978 0 580 73776 3ICS 65.160Compliance with a British Stand
4、ard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 April 2013.Amendments issued since publicationDate Text affectedBS ISO 2971:2013 ISO 2013Cigarettes and filter rods Determination of nominal di
5、ameter Method using a non-contact optical measuring apparatusCigarettes et btonnets-filtres Dtermination du diamtre nominal Mthode utilisant un instrument de mesure optique sans contactINTERNATIONAL STANDARDISO2971Fourth edition2013-04-01Reference numberISO 2971:2013(E)BS ISO 2971:2013ISO 2971:2013(
6、E)ii ISO 2013 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2013All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an i
7、ntranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublis
8、hed in SwitzerlandBS ISO 2971:2013ISO 2971:2013(E) ISO 2013 All rights reserved iiiContents PageForeword iv1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 25 Apparatus . 26 Sampling 37 Procedure. 37.1 Preparation of test pieces 37.2 Adjustment and calibration . 47.3 Measure
9、ment 48 Expression of results 49 Repeatability and reproducibility 510 Test report . 5Annex A (normative) Calibration standards 7Annex B (informative) Measurement principle and required number of scans . 8Annex C (informative) Information on possible source of measurement error.10Annex D (informativ
10、e) Non-contact measurement techniques .12Annex E (informative) Alternative measurement techniques for the determination of nominal diameter of cigarettes and filter rods 15Annex F (informative) Protocol for ISO/TC 126/SC 1/WG 2 interlaboratory diameter measurement uncertainty study 17BS ISO 2971:201
11、3ISO 2971:2013(E)ForewordISO (the International Organization for Standardization) is a worldwide federation 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 subje
12、ct for which a technical committee has been established has the right to be represented on that committee. 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
13、) on all matters of electrotechnical standardization.International Standards are drafted in accordance 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
14、 are circulated to the member bodies for voting. Publication as an International Standard requires 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
15、 responsible for identifying any or all such patent rights.ISO 2971 was prepared by Technical Committee ISO/TC 126, Tobacco and tobacco products, Subcommittee SC 1, Physical and dimensional tests.This fourth edition cancels and replaces the third edition (ISO 2971:1998), which has been technically r
16、evised.iv ISO 2013 All rights reservedBS ISO 2971:2013INTERNATIONAL STANDARD ISO 2971:2013(E)Cigarettes and filter rods Determination of nominal diameter Method using a non-contact optical measuring apparatus1 ScopeThis International Standard specifies a non contact, optical method of gauging for de
17、termination of the mean, minimum and maximum diameters and the ovality (or roundness) of rod-shaped objects with a nominally circular or oval cross section that is convex curvilinear. The method is applicable, in particular, to cigarettes and filter rods.NOTE 1 Non-contact measurement techniques are
18、 discussed in Annex D.NOTE 2 Alternative contact or pneumatic methods may be used but should be considered as secondary methods and do not come within the scope of the standard. These alternative measurement techniques are discussed in Annex E.2 Normative referencesThe following documents, in whole
19、or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 3402, Tobacco and tobacco products Atm
20、osphere for conditioning and testingISO 5725-2:1994, Accuracy (trueness and precision) of measurement methods and results Part 2: Basic method for the determination of repeatability and reproducibility of a standard measurement method3 Terms and definitionsFor the purposes of this International Stan
21、dard, the following terms and definitions apply.3.1diameterarithmetical mean value of n apparent diameters measured on a test piece following the method specified in this International Standard, which represents the diameter of a circle with the same circumference as the perimeter of the sample bein
22、g measured, provided that the boundary of its cross section is convexNote 1 to entry: The result of the measurement can be affected by n, the number of readings taken.3.2convex cross sectiona cross section where the straight line between any two points from the section is also included within the se
23、ction3.3perimeterlength of the line that is the boundary of the cross sectionNote 1 to entry: Errors will exist in the estimated value of the perimeter if the sample is not circular. The error will increase as the ovality increases.3.4circumferenceperimeter of a circular cross section ISO 2013 All r
24、ights reserved 1BS ISO 2971:2013ISO 2971:2013(E)3.5minimum diameterminimum value obtained from the results of n individual readings performed on a test piece3.6maximum diametermaximum value obtained from the results of n individual readings performed on a test piece3.7absolute ovalityexpression of t
25、he out-of-roundness of a rod-like test piece, which is obtained from the arithmetic difference between the maximum and minimum diameters obtained from n individual readings3.8relative ovalityratio of the absolute ovality and the diameter, expressed as a percentage3.9relative roundness100 minus relat
26、ive ovalityNote 1 to entry: Caution should be exercised in interpreting maximum diameters, absolute ovality, relative ovality and relative roundness as these can be affected by the quality of the gum line (raised laps) or other product defects, generating erroneous individual readings.4 PrincipleThe
27、 principle of measurement of the mean diameter of a shape having a convex cross section follows the generalization of Barbiers Theorem, which states that the mean diameter of a section is equal to the arithmetic mean of the apparent (or projected) diameters of the section as it is rotated at equiang
28、ular intervals in the field of view. It is required that the section is rotated by an integer multiple of 180.NOTE The principle is demonstrated in Annex B.1.5 Apparatus5.1 Sample conditioning enclosure, to be capable of maintaining the conditions given in ISO 3402.5.2 Optical measuring apparatus, t
29、o consist of the following.5.2.1 Optical measuring instrumentThis must have an uncertainty of no more than 0,01 mm and be suitable for the determination of the diameter of rod-like test pieces with a nearly circular cross section. A schematic diagram of such an instrument is presented in Figure 1 an
30、d three different implementations are described in Annex D.The scanning rate of the instrument shall be such that no eccentric motion of the test piece parallel to the longitudinal axis, within the measurement area, shall affect the accuracy of the measurement of mean diameter.The ratio between the
31、scanning rate of the apparatus and the rotational speed of the test piece shall be constant and high enough to ensure that the measured diameter, as well as the minimum and maximum values, shall be determined with sufficient accuracy, despite the possible ovality of the test piece.The length of the
32、scan path shall be sufficiently greater than the maximum diameter to be measured to avoid errors due to test piece eccentricity. The test piece shall be scanned a minimum of 32 times during a half-rotation (180) or 64 times during a full (360) rotation.NOTE The rationale for the required number of s
33、cans is presented in Annex B.2.2 ISO 2013 All rights reservedBS ISO 2971:2013ISO 2971:2013(E)5.2.2 Apparatus or fixture for rotating the test piece or scan pathThis shall rotate the test piece within the measurement area or rotate the direction of view around the test piece while maintaining the lon
34、gitudinal axis of the test piece perpendicular to the measurement area during a full 360 rotation.Key1 test piece2 test piece longitudinal axis and axis of rotation3 plane of the measurement4 measurement centreline5 measurement area6 test piece cross section7 projection plane8 apparent diameter (ort
35、hogonal projection or image) of the test piece cross sectionFigure 1 Diagram of a generic non-contact optical gauging system6 SamplingTake a statistically representative sample of the population of test pieces to be characterized.Samples shall be free of obvious visible defects which may affect the
36、measurement.7 Procedure7.1 Preparation of test piecesCondition the test pieces, prior to measurement, in a conditioning enclosure in accordance with ISO 3402.Select at random, from the sample taken in accordance with Clause 6, the number of test pieces required for the test. ISO 2013 All rights rese
37、rved 3BS ISO 2971:2013ISO 2971:2013(E)The time required for the curing of filter rods and the duration of conditioning for both filter rods and cigarettes are not specified in this International Standard and are to be determined by practical experience. They shall be reported in the test report toge
38、ther with the results.7.2 Adjustment and calibrationWorking standards are routinely used to adjust calibrate or check the calibration of the measurement system. Calibration shall be performed in accordance with the manufacturers instructions.NOTE The essential properties of calibration standards are
39、 given in Annex A.7.3 MeasurementIn accordance with the manufacturers instructions, position the test piece within the measurement area, as close as possible to the centre of the measurement area.The test piece, or the measuring apparatus, shall be capable of being rotated around the rotation axis s
40、uch that any eccentric motion of the test piece, relative to the plane of the measurement, remains in parallel with the plane of the measurement and perpendicular to the longitudinal axis of the test piece.Adjust the instrument and/or feeding and rotational apparatus for the plane of the measurement
41、 to measure the required section of the test piece.Operate the apparatus in accordance with the manufacturers instructions and accurately record the mean, minimum and maximum diameters.At least 10 test pieces from one sample shall be used to determine the mean value of the diameter for the sample.NO
42、TE 1 In practice, laboratories often take a different number of measurements depending on the application of the measurement.NOTE 2 Possible sources of error in measurement of diameter are given in Annex C.8 Expression of resultsThe value of the sample mean diameter shall be the mean value of the in
43、dividual measurements. See 7.3.The results shall be expressed as follows:a) diameter, the arithmetic average of at least 64 individual scans per full revolution or 32 scans per half revolution, is expressed in millimetres to the nearest 0,01 mm ;b) sample mean diameter, the average of x diameter mea
44、surements (x is normally 10 but may vary; see note 1 in 7.3) is expressed in millimetres to the nearest 0,001 mm ;c) sample maximum diameter, the maximum diameter obtained from a sample of x test pieces, is expressed in millimetres to the nearest 0,01 mm ;d) sample minimum diameter, the minimum diam
45、eter obtained from a sample of x test pieces, is expressed in millimetres to the nearest 0,01 mm ;e) absolute ovality is expressed in millimetres to the nearest 0,01 mm ;f) relative ovality is expressed as a percentage to the nearest 0,1 % ;g) relative roundness is expressed as a percentage to the n
46、earest 0,1 %.4 ISO 2013 All rights reservedBS ISO 2971:2013ISO 2971:2013(E)9 Repeatability and reproducibilityAn international collaborative study involving 14 laboratories was conducted according to ISO 5725-2:1994 in 2009 on matched samples of both filter rods and cigarettes covering a range of ap
47、proximately 5 mm to 9 mm diameter.Each measured sample was drawn randomly from a population of typically 3000 rods that, as far as was possible, represented a consistent production process. Three samples of 10 rods, plus spares, were distributed to each participant. Each sample of 10 rods was measur
48、ed once only. The measurement position for the cigarettes was specified to be on the tobacco column. The measurement position for the filters was not specified.NOTE 1 Specific details of the measurement protocol are given in Annex F.The study gave the following values (see Table 1) for mean diameter
49、, repeatability standard deviation (sr), reproducibility standard deviation (sR), repeatability limit (r) and reproducibility limit (R). The values derived from this interlaboratory study may not be applicable to values and matrices other than those given because the samples being used did not cover all available products.Table 1 Summary of results of collaborative studyProduct typeMean diameter srsRr RCommentmm mm mm mm mmMono acetate filter rods, nom-inally circular cross section5,335 0,0039 0,0157 0,011 0,044 Non porous6,
