ISO 12030-2010 Tobacco and tobacco products - Non-destructive determination of strips density variation ratio in case - Ionizing radiation method《烟草和烟草产品 案例中带状密.pdf

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1、 Reference number ISO 12030:2010(E) ISO 2010INTERNATIONAL STANDARD ISO 12030 First edition 2010-05-01 Tobacco and tobacco products Non- destructive determination of strips density variation ratio in case Ionizing radiation method Tabac et produits du tabac Dtermination non destructive de la variatio

2、n de densit des strips en caisse Mthode par radiations ionisantes ISO 12030:2010(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed

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5、t is found, please inform the Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT ISO 2010 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying

6、 and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland

7、 ii ISO 2010 All rights reservedISO 12030:2010(E) ISO 2010 All rights reserved iiiContents Page Foreword iv Introduction.v 1 Scope1 2 Normative references1 3 Terms and definitions .1 4 Principle1 5 Apparatus.2 6 Procedure.3 6.1 Sampling.3 6.2 Experimental protocol.3 6.3 Distribution of detection spo

8、ts 4 6.4 Determination of water content .4 6.5 Determination of density 4 7 Expression of results5 8 Test report5 Annex A (normative) Determination of the density of standard pieces and calibration of density determination instrument .6 Annex B (informative) Main components of X-ray device 8 Bibliog

9、raphy10 ISO 12030:2010(E) iv ISO 2010 All rights reservedForeword ISO (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 committee

10、s. 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, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the Inter

11、national Electrotechnical Commission (IEC) 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 St

12、andards 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 member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the sub

13、ject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 12030 was prepared by Technical Committee ISO/TC 126, Tobacco and tobacco products, Subcommittee SC 2, Leaf tobacco. ISO 12030:2010(E) ISO 2010 All rights reserved vIntroduction The density va

14、riation ratio (DVR) is one of the significant factors that influence tobacco aging and primary processing (see Reference 1). For example, the phenomena of oil loss, caking or even carbonization is easy to take place in an aging process because of the larger DVR. The block of strips, which has a larg

15、er DVR, is difficult to loosen in a conditioning cylinder. The larger DVR can lead to deterioration of taste and quality of cigarette and hence it is important to detect DVR of strips still in its case (i.e. before introducing it into a primary processing stream). The standard method for detecting D

16、VR of strips in case, used at present, is based on “9-point Static Detection (see Reference 2). This method results in damage to strips, being applicable for only off-line measurements and needing longer testing time. A non-destructive method, on the other hand, would be quicker, amenable to both of

17、f-line and on-line measurements and would result in no damage to strips and hence has been a subject of analytical research and development. X-rays can easily penetrate the strips case and their intensity correlates to the density of the material they pass through, which would be a strips column in

18、the case. The ionizing method has been widely used in many other areas (see IEC 60692 3 ) and IEC has developed relevant standards for safe X-ray apparatus (see IEC 60405 4 ). The X-ray apparatus used in the proposed method complies with these International Standards and can therefore be considered

19、to be a completely safe radiation source. Thus the ionizing radiation (X-ray attenuation) method retains the advantages of a non-destructive method for measurement of density of strips in the case, is amenable for on-line as well off-line measurements, is quick, safe and relatively inexpensive. The

20、present proposal elaborates on its application for measurement of density of strips in the case. There are more possibilities of measuring the density variation ratio in case. Any system with the same accuracy can be used. INTERNATIONAL STANDARD ISO 12030:2010(E) ISO 2010 All rights reserved 1Tobacc

21、o and tobacco products Non-destructive determination of strips density variation ratio in case Ionizing radiation method 1 Scope This International Standard specifies a method for determining density variation ratio (DVR) of strips in the case. 2 Normative references The following referenced documen

22、ts 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 6488, Tobacco and tobacco products Determination of water content Karl Fische

23、r method ISO 16632, Tobacco and tobacco products Determination of water content Gas-chromatographic method 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 non-destructive determination determination without any damage to the objects under stu

24、dy 3.2 density variation ratio DVR relative standard deviation of the strips density in case 4 Principle The X-rays penetrate the tobacco strips in the case and lose their intensity depending on the density of the strips. The measured intensity of X-rays can thus be related to strips density accordi

25、ng to Equation (1). i m0 1 ln I UdIB = (1) ISO 12030:2010(E) 2 ISO 2010 All rights reservedwhere is the strips density; u mis the mass attenuation coefficient; d is the thickness of strips (case height); I iis the intensity of X-rays after penetrating strips column; I 0is the initial intensity of X-

26、rays; B is the scattering factor. The principle is illustrated in Figure 1. Key 1 X-ray source 4 strips case 2 collimation hole 5 NaI detector 3 X-ray beam Figure 1 Principle of measurement 5 Apparatus 5.1 X-ray apparatus, complying with the following requirements. See Figure 2. a) main components:

27、one or three pairs of X-ray-producing tubes and X-ray detectors (see Annex B); b) resolution: at least 1 kg/m 3for strips density; c) scope: 100 kg/m 3to 600 kg/m 3for strips density; d) zero-drift: not more than 1 % over 24 h period; e) output: density value of nine different detecting spots, 1 , 2

28、 9 ; DVR value; f) safety requirement: maximum X-ray dose of 2,5 Sv/h at 1,0 m distance. ISO 12030:2010(E) ISO 2010 All rights reserved 35.2 Analytical balance, with an accuracy of 0,1 g. Key 1 X-ray-producing device 2 strips case 3 X-ray detector 4 conveyer belt 5 radiation shield Figure 2 Schemati

29、c diagram of X-ray apparatus 6 Procedure 6.1 Sampling 6.1.1 On-line determination Every strips case shall be subjected to density determination. 6.1.2 Off-line determination The recommended sampling rate for strips cases to be subjected for density determination is 2 %. If the total number of cases

30、is less than 100, at least two cases representing the entire lot shall be subjected to density determination. 6.2 Experimental protocol The main components of the instrument are the X-ray sources (5.1) with one or three pairs of X-ray-producing tubes and sensitive X-ray detectors. The X-ray-producin

31、g tubes emit X-rays constantly and the X-ray detector measures the intensity of the X-rays after they have passed through strips column in the strips case. The density determination device is fixed over a conveyor belt that carries the strips case. The number and location of detecting spots is given

32、 in 6.3. The density value of nine different detection spots is determined as a first result, and then the DVR value is calculated. ISO 12030:2010(E) 4 ISO 2010 All rights reserved6.3 Distribution of detection spots The distribution of detection spots is shown in Figure 3. Figure 3 Distribution of n

33、ine detection spots (top view of strips case) The rectangle ABCD represents the top view of a typical strips case as placed under the X-ray device. Line 1 (L1), Line 2 (L2) and Line 3 (L3) are parallel with the edge AC; Line 4 (L4), Line 5 (L5) and Line 6 (L6) are parallel with edge AB. Detection sp

34、ot locations are indicated by intersections of these lines viz., spots a, b, c, d, e, f, g, h and i. Spot e is the centre of the top view of strips case. The distances between L1 and edge AC, L3 and edge BD, L4 and edge AB, L6 and edge CD are the same, being one eighth of the length of the strips ca

35、se (edge AB). 6.4 Determination of water content Water content is determined in accordance with ISO 6488 or ISO 16632. Although the water content is not used in determining DVR, it may affect the results. The water content should, therefore, be determined and reported. 6.5 Determination of density 6

36、.5.1 Calibration The density determination instrument is calibrated with five standard pieces (plexiglass tubes containing strips with different densities) before actual usage as described in Annex A. 6.5.2 Determination of density The intensity of X-rays (initial and after passing through strips co

37、lumn in strips case) is measured at nine spots and used to calculate strips density in nine different spots in the case. CAUTION Use the radiation shield as needed for safe operation. ISO 12030:2010(E) ISO 2010 All rights reserved 57 Expression of results The DVR value is calculated using the nine d

38、ensity values measured at nine different spots i.e. 1 , 2 9according to Equation (2). sd DVR 100 % = (2) where DVR is the density variation ratio of strips in case, in percent; sdis the standard deviation of nine different detecting spots, in kilograms per cubic metre; is the average density value o

39、f nine different detecting spots, in kilograms per cubic metre. 8 Test report The test report shall include the following details: a) all information necessary for the complete identification of the sample(s); b) method and date of sampling; c) date of testing; d) water content, as a mass fraction i

40、n percent; e) the analysis results and the units in which they are reported; f) any special features observed during the analysis; g) any working conditions that are not specified in this method or are considered as optional and that may have affected the results. ISO 12030:2010(E) 6 ISO 2010 All ri

41、ghts reservedAnnex A (normative) Determination of the density of standard pieces and calibration of density determination instrument A.1 Standard pieces Standard pieces are plexiglass cylinders with an outer diameter of 59 mm, a wall thickness of 5 mm with the tolerance being 0,1 mm and the height b

42、eing equal to that of strips case. Two pieces of disc of the same material and thickness as the strips case are put in the two ends of standard pieces. The standard pieces are filled with the sample strips. A.2 Determination of the density of standard pieces The density of standard pieces is calcula

43、ted by gravimetric method according to Equation (A.1). 1 actual W V = (A.1) where actualis the actual density value of a standard piece, in kilograms per cubic metre; W 1is the mass of strips within a standard piece, in kilograms; V is the volume of a standard piece, in cubic metres. A.3 Calibration

44、 The density determination instrument needs to be calibrated before use. It is calibrated by five standard pieces with different densities between 200 kg/m 3and 500 kg/m 3 . It is recommended to use the strips with similar water content in the calibration tubes. The schematic diagram of the calibrat

45、ion apparatus is shown in Figure A.1. Input the actual density value into the communication interface. The apparatus is adjusted automatically according to the actual density value and its corresponding I i . ISO 12030:2010(E) ISO 2010 All rights reserved 7Key 1 X-ray source 2 collimation hole 3 X-r

46、ay beam 4 plexiglass cylinder 5 NaI detector Figure A.1 Calibration of density determination instrument with standard piece A.4 Principle of calibration using standard pieces The density value of a standard piece and the X-ray intensity after penetrating the material have the relationship shown by E

47、quation (A.2). i 0 ln( ) I K C I =+ (A.2) where K is a coefficient equal to m 1 ; ud C is a coefficient equal to m 1 ln( ). B ud K and C can be calculated from the corresponding actualand I i , and will be set as the defaults for particular samples. ISO 12030:2010(E) 8 ISO 2010 All rights reservedAn

48、nex B (informative) Main components of X-ray device B.1 Principle of producing X-rays A glass envelope under high vacuum, with a wire element at one end forms the cathode, and a heavy target at the other end forms the anode. Electrons from the cathode are accelerated on to a positively-charged anode

49、 by means of a high voltage. When electrons hit this material, some of the electrons will approach the nucleus of the metal atoms where they are deflected because of their opposite charges (electrons are negative and the nucleus is positive). This deflection causes the energy of the electrons to decrease, and this decrease in energy then results in forming an X-ray. X-rays are emitted from the anode in all directions. Shielding is used to create a