ISO 4150-2011 Green coffee or raw coffee - Size analysis - Manual and machine sieving《生咖啡或咖啡原料粒度分析 人工和机器筛选》.pdf

1、Green coffee or raw coffee Size analysis Manual and machine sieving Caf vert Analyse granulomtrique Tamisage manuel et la machine ISO 2011 Reference number ISO 4150:2011(E) Third edition 2011-11-15 ISO 4150 INTERNATIONAL STANDARDISO 4150:2011(E)COPYRIGHT PROTECTED DOCUMENT ISO 2011 All rights reserv

2、ed. 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 and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requeste

3、r. 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 ii ISO 2011 All rights reservedISO 4150:2011(E) ISO 2011 All rights reserved iii Contents Page Foreword iv 1 Scope 1 2 Normative ref

4、erences . 1 3 Terms and definitions . 1 4 Principle . 1 5 Apparatus 1 6 Sampling . 2 7 Procedure 3 7.1 Test portion . 3 7.2 Selection of sieves 3 7.3 Sieving and weighing . 3 7.4 Additional observations 3 8 Statement of results . 4 9 Precision 4 9.1 General . 4 9.2 Repeatability . 4 9.3 Reproducibil

5、ity . 4 10 Test report . 4 Annex A (normative) Characteristics of perforated metal plate test sieves with round holes 6 Annex B (normative) Characteristics of perforated metal plate test sieves with slotted apertures 8 Annex C (informative) Interlaboratory . 9 Annex D (informative) Verification of m

6、echanical equipment of sieving machines .10 Bibliography .12Foreword 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 commit

7、tees. 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 In

8、ternational 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

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

10、subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 4150 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 15, Coffee. This third edition cancels and replaces the second edition (ISO 4150:1991), which has been tec

11、hnically revised. ISO 4150:2011(E)iv ISO 2011 All rights reservedINTERNATIONAL STANDARD ISO 4150:2011(E)Green coffee or raw coffee Size analysis Manual and machine sieving 1 Scope This International Standard specifies a routine method for carrying out size analysis of green coffee by manual and mach

12、ine sieving using laboratory test sieves. 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 amend

13、ments) applies. ISO 3, Preferred numbers Series of preferred numbers ISO 2395, Test sieves and test sieving Vocabulary ISO 2591-1, Test sieving Part 1: Methods using test sieves of woven wire cloth and perforated metal plate ISO 3310-2, Test sieves Technical requirements and testing Part 2: Test sie

14、ves of perforated metal plate ISO 3509, Coffee and coffee products Vocabulary ISO 4072, Green coffee in bags Sampling 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 2395 (for test sieves) and ISO 3509 (for coffee) apply. 4 Principle A laboratory sam

15、ple is separated into fractions according to size by manual (or machine) sieving, and the results are expressed as percentage mass fractions. 5 Apparatus 5.1 Balance, capable of weighing to the nearest 0,1 g. 5.2 Nest of test sieves. For the dimensions and sieving medium, the test sieves shall have

16、a sieve surface area of between 550 cm 2and 1 000 cm 2 . Suitable test sieves are, for example, square sieves of size 300 mm, complying with the requirements of ISO 2591-1, except that the approximate depth of the sieve may be reduced to 25 mm. The perforated metal plate used as the sieving medium s

17、hall be made of metal of suitable strength, such as stainless steel, ordinary steel or zinc, 0,8 mm to 1 mm thick. Each plate shall be perforated in accordance with the requirements given in Annex A or Annex B. The test sieves shall be marked by means of a label attached to the sieve giving the foll

18、owing details: a) traditional numbering (see Annex A); ISO 2011 All rights reserved 1NOTE The traditional numbering is given for information purposes. It corresponds to the nominal aperture size of round apertures or to the width of slotted apertures, expressed in 64ths of an inch, closest to the me

19、tric dimension adopted. b) nominal aperture size or the dimensions of slotted apertures (see Annex B); c) in the case of round holes, the diameter of the sieve current is determined in the verification (see Annex A); d) reference to the International Standard(s) with which the sieve complies; e) mat

20、erial of the sieving medium and that of the frame; f) name of the firm (manufacturer or vendor) taking responsibility for the sieve; g) identification number. In terms of construction, the test sieve frames shall nest snugly with each other and with the lid and receiver. The frame shall be smooth an

21、d the seal of the sieve so constructed as to prevent lodging of the coffee beans being sieved. For verification, new test sieves shall be tested (for example using the methods described in ISO 3310-2) and a certificate shall be available to this effect. Periodic checking should also be performed, si

22、nce some changes in the dimensions of the apertures can occur after a period of use. 5.3 Test sieves. 5.3.1 Test sieves with round holes, 11 sieves (see Annex A). 5.3.2 Test sieves with slotted holes, 7 sieves (see Annex B). 5.4 Lid. The lid shall comply with the requirements of ISO 2591-1. 5.5 Rece

23、iver. The receiver shall comply with the requirements of ISO 2591-1. 5.6 Machine for sieving, having the following features. a) The results obtained over each sieve shall be equal to using the manual method. In Annex D, a guide is presented to carry out this verification. b) The machine shall contai

24、n a tray to allow for the assembly of a set with any number of sieves in order to carry out a complete analysis. c) It shall consist of sieves which are easy to fix. d) It shall have an adjustable timer in the 0 min to 3 min range. 6 Sampling Take a laboratory sample of 300 g, prepared in accordance

25、 with ISO 4072. NOTE The same laboratory sample as used for the examination and determination described in ISO 4149 can be used for the purposes of this International Standard, provided the sample is fully reconstituted before the test portion is taken for the test sieving. ISO 4150:2011(E)2 ISO 201

26、1 All rights reserved7 Procedure 7.1 Test portion Weigh, to the nearest 0,1 g, 300 g of the laboratory sample. 7.2 Selection of sieves Select a nest of sieves (5.2) with round apertures (5.3.1). Assemble the sieves in descending order of aperture size. If dealing with a sample of substantially peabe

27、rry coffee, to determine the percentage mass fraction of peaberry in the test portion, use a sieve with slotted openings (5.3.2). Discard the sieves with larger apertures through which all beans can pass. NOTE The common sieve numbers are 18, 17, 16, 15, 14 and 12. Place the receiver (5.5) under the

28、 sieve with the smallest apertures. 7.3 Sieving and weighing Pour the test portion (7.1) on to the upper sieve and put the lid (5.4) in place. 7.3.1 Manual sieving 7.3.1.1 Spread a clean, dry, soft cloth under the receiver, in order to obtain smooth sliding. Spread the cloth (see 7.2) over a flat su

29、rface and then put the nest of sieves on it. 7.3.1.2 Agitate uniformly the nest of sieves for 3 min, one way (back and forth) without raising it from the surface at a speed of between 110 cycles per min and 130 cycles per min with a displacement of 10 cm approximately. NOTE A speed with 150 cycles p

30、er min and 160 cycles per min and a displacement of 5 cm can be used. If using slotted aperture sieves, agitate in a direction parallel to the length of apertures. Beans remaining in apertures shall be considered to be retained on the sieve in question. Remove all the beans from each sieve separatel

31、y, to avoid loss of the beans. Put the lid on the top of the respective sieve, then put one hand under the sieve and push the beans up. Then, carefully place the beans on a tray. 7.3.1.3 Weigh to the nearest 0,1 g, the beans collected on each of the sieves used and in the receiver. 7.3.2 Machine sie

32、ving 7.3.2.1 Put the nest of sieves on the machine (5.6) firmly, and turn the equipment on for 3 min. If using slotted aperture sieves, agitate in a direction parallel with the length of apertures. Beans remaining in apertures shall be considered to be retained on the sieve in question. 7.3.2.2 Remo

33、ve all the beans from each sieve separately, to avoid loss of the beans. Put the lid on the top of the respective sieve, then put one hand under the sieve and push the beans up. Then, carefully place the beans on a tray. 7.3.2.3 Weigh to the nearest 0,1 g, the beans collected on each of the sieves u

34、sed and in the receiver. 7.4 Additional observations Note whether any of the fractions contains a significant proportion of foreign matter, bean fragments or broken beans. In this case, apply ISO 4149. ISO 4150:2011(E) ISO 2011 All rights reserved 38 Statement of results 8.1 The result, w gc , is ex

35、pressed as a mass fraction retained over each sieve in the following manner: where w gcis the mass fraction retained with the sieve number, S; m Sis the coffee bean mass, with the sieve number, S, expressed in grams; m Tis the total mass of the sample, expressed in grams. 8.2 The total percentage of

36、 all sieves shall be equal to (100 0,5) % of the mass of the test portion. If this is not the case, the test is not valid and shall be repeated using another laboratory sample. 9 Precision 9.1 General The results of an interlaboratory test are given in Annex C. 9.2 Repeatability The absolute differe

37、nce between two single test re sults for a given sieve size, S, obtained using the same method on the identical test material in the same laboratory by the same operator using the same equipment within a short interval of time, should not be greater than the repeatability limit, r S , for this sieve

38、 r S= 2,8 S r= 0,0187 w S+ 0,099 1 where w Sis the mean of the results on the respective sieve. 9.3 Reproducibility The absolute difference between two single test re sults for a given sieve size, S, obtained using differ ent equipment, should not be greater than the re producibility limit, R S , f

39、or this sieve. R S = 2,8 S R= 0,1237 w S+ 0,590 9 where w Sis the mean of the results on the respective sieve. 10 Test report The test report shall contain at least the following information: a) reference to this International Standard, i.e. ISO 4150:2011; b) all the information necessary for the co

40、mplete identification of the sample; c) specification of the method and type of sieve used; d) the test result(s) obtained; e) the details of any foreign matter or defect found and recorded in accordance with 7.4; ISO 4150:2011(E)4 ISO 2011 All rights reservedf) all operating details not specified i

41、n this International Standard or regarded as optional, together with any incidents which can have influenced the result(s). ISO 4150:2011(E) ISO 2011 All rights reserved 5Annex A (normative) Characteristics of perforated metal plate test sieves with round holes The sequence of aperture diameters is

42、taken from the R 40 series of preferred numbers in ISO 3. The sieves numbers 7, 10, 12, 121/2, 14, 15, 16, 17, 18, 19 and 20 shall comply with the requirements of ISO 3310-2, except that the tolerance on the normal diameter shall be as shown in Table A.1. The technical specifications of sieves numbe

43、rs 15 and 19 shall be obtained by interpolation from those given in ISO 3310-2, except that the tolerance on the normal diameter shall be as shown in Table A.1. The arrangement of the apertures shall be such that the aperture centres are at the apices of equilateral triangles (see Figure A.1). Table

44、 A.1 Characteristics of perforated metal plate test sieves with round holes Aperture size mmSieve number Nominal diameter w Tolerance 8,00 7,50 7,10 6,70 6,30 6,00 5,60 5,00 4,75 4,00 2,80 0,09 0,09 0,09 0,08 0,08 0,08 0,07 0,07 0,07 0,06 0,05 20 19 18 17 16 15 14 12 1/2 12 10 7 ISO 4150:2011(E)6 IS

45、O 2011 All rights reservedKey p pitch w hole size NOTE Values of the pitch, p, are given in ISO 3310-2. Figure A.1 Round holes Staggered arrangement ISO 4150:2011(E) ISO 2011 All rights reserved 7Annex B (normative) Characteristics of perforated metal plate test sieves with slotted apertures The seq

46、uence of slot widths is taken from the R 40 series of preferred numbers in ISO 3. The slots shall be arranged in rows (see Figure B.1) or staggered. The values given for the pitches should be regarded as a nominal guide. Table B.1 Characteristics of perforated metal plate test sieves with slotted ap

47、ertures Aperture size mm Pitch mm Sieve number Width w 1 Tolerance on width Length w 2 p 1 p 2 5,60 5,00 4,75 4,50 4,00 3,55 3,00 0,07 0,07 0,07 0,07 0,06 0,06 0,05 30 30 20 20 20 20 20 9,6 9,0 8,6 8,2 7,5 6,8 6,0 36 36 25 or 26 25 or 26 25 or 26 25 or 26 25 or 26 14 13 12 11 10 9 8 Key p 1width pit

48、ch p 2length pitch w 1hole width w 2hole length Figure B.2 Slotted apertures Arrangement in rows ISO 4150:2011(E)8 ISO 2011 All rights reservedAnnex C (informative)Interlaboratory An interlaboratory test carried out in 2005, in which 17 laboratories participated, each of which carried two determinat

49、ions on the sample, gave the statistical results (evaluated in accordance with ISO 5725-2) shown in Table C.1. Table C.1 Determination of values of means ( w S ), S rand S R Sieve 18 17 16 15 14 12 Receiver Number of laboratories retained after eliminating outliers 17 17 17 17 17 17 17 Mean ( w S ), % 24,27 32,16 24,30 11,39 5,38 2,07 0,43 Standard deviation of repeatability, S r 0,23 0,26 0,14 0,11 0,10 0,05 0,02 Coefficient of vari