1、BS EN ISO7971-2:2009ICS 67.060NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDCereals Determination of bulkdensity, called massper hectolitrePart 2: Method of traceability formeasuring instruments throughreference to the international standardinstrument (ISO 797
2、1-2:2009)This British Standardwas published underthe authority of theStandards Policy andStrategy Committee on 30November 2009. BSI 2009ISBN 978 0 580 58446 6Amendments/corrigenda issued since publicationDate CommentsBS EN ISO 7971-2:2009National forewordThis British Standard is the UK implementatio
3、n of EN ISO 7971-2:2009.The UK participation in its preparation was entrusted to TechnicalCommittee AW/4, Cereals and pulses.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a
4、contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 7971-2 August 2009 ICS 67.060 English Version Cereals - Determination of bulk density, called mass per
5、hectolitre - Part 2: Method of traceability for measuring instruments through reference to the international standard instrument (ISO 7971-2:2009) Crales - Dtermination de la masse volumique, dite masse lhectolitre - Partie 2: Mthode de raccordement des instruments de mesure ltalon international (IS
6、O 7971-2:2009) Getreide - Bestimmung der Schttdichte, sogenannte Masse je Hektoliter - Teil 2: Verfahren zur Rckverfolgbarkeit von Messgerten mittels Referenz auf internationale Normalgerte (ISO 7971-2:2009) This European Standard was approved by CEN on 8 August 2009. CEN members are bound to comply
7、 with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of 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 Managemen
8、t Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). 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 Management Centre has the same status as the o
9、fficial versions. 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, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia,
10、 Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2009 CEN All rights of exploitation in any form and by any means reserved worldwide for
11、CEN national Members. Ref. No. EN ISO 7971-2:2009: EBS EN ISO 7971-2:2009EN ISO 7971-2:2009 (E) 3 Foreword This document (EN ISO 7971-2:2009) has been prepared by Technical Committee CEN/TC 338 “Cereal and cereal products”, the secretariat of which is held by AFNOR, in collaboration with Technical C
12、ommittee ISO/TC 34 “Food products“. 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 February 2010, and conflicting national standards shall be withdrawn at the latest by February 2010. Attention i
13、s 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 national standards organizations of the fo
14、llowing countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, S
15、lovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN ISO 7971-2:2009ISO 7971-2:2009(E) ISO 2009 All rights reserved iiiContents Page Foreword iv 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 1 4 Requirements 2 4.1 Certified international or national standard instrument
16、 . 2 4.2 National standard instrument 2 4.3 Secondary or internal standard instrument.2 4.4 Routine measuring instrument 2 5 Principle. 3 6 Apparatus 3 7 Procedure 4 7.1 Traceability of national standard instruments through reference to the certified international or national standard instrument.4 7
17、.2 Traceability of the secondary standard instruments through reference to the national standard instrument . 6 7.3 Verification of instruments in operation. 7 8 Monitoring of instrument performance 9 9 Test reports . 9 9.1 Analysis certificate . 9 9.2 Conformity certificate. 10 10 Identification of
18、 traced measuring instruments 10 Annex A (normative) Method for calculation of performance parameters of standard instruments and of measurement instruments. 11 Annex B (informative) Some owners of certified standard measurement instruments 18 Bibliography . 19 BS EN ISO 7971-2:2009ISO 7971-2:2009(E
19、) iv ISO 2009 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 committees. Each member body inte
20、rested 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 International Electrotechnica
21、l 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 Standards adopted by the t
22、echnical 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 subject of patent rights. I
23、SO shall not be held responsible for identifying any or all such patent rights. ISO 7971 (all parts) was prepared by the European Committee for Standardization (CEN) Technical Committee CEN/TC 338, Cereal and cereal products, in collaboration with Technical Committee ISO/TC 34, Food products, Subcom
24、mittee SC 4, Cereals and pulses, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement). This edition is the second to bear the number ISO 7971-2, but the technical content is new. ISO 7971-3:2009 cancels and replaces the first edition (ISO 7971-2:1995). ISO
25、 7971 consists of the following parts, under the general title Cereals Determination of bulk density, called mass per hectolitre: Part 1: Reference method Part 2: Method of traceability for measuring instruments through reference to the international standard instrument Part 3: Routine method BS EN
26、ISO 7971-2:2009INTERNATIONAL STANDARD ISO 7971-2:2009(E) ISO 2009 All rights reserved 1Cereals Determination of bulk density, called mass per hectolitre Part 2: Method of traceability for measuring instruments through reference to the international standard instrument 1 Scope This part of ISO 7971 s
27、pecifies a test method for ensuring the traceability of mass per hectolitre measuring instruments through reference to standard measurement instruments. The mass per hectolitre or bulk density is of commercial importance for grain cereals. Several types of instruments with varying performances exist
28、 for measuring it. This part of ISO 7971 also specifies the performances required of national standards instruments, secondary standards instruments, and measuring instruments used in laboratories or in collection or storage silos. 2 Normative references The following referenced documents are indisp
29、ensable 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 712, Cereals and cereal products Determination of moisture content Reference method ISO 79
30、71-1, Cereals Determination of bulk density, called “mass per hectolitre” Part 1: Reference method 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 bulk density “mass per hectolitre” cereals ratio of the mass of a cereal to the volume it occup
31、ies after being poured into a container under well-defined conditions NOTE Bulk density is expressed in kilograms per hectolitre of grains as received. ISO 7971-1:2009 3.2 traceability cereals establishment of a relationship between the usual measuring instrument and the international standard instr
32、ument via a chain BS EN ISO 7971-2:2009ISO 7971-2:2009(E) 2 ISO 2009 All rights reserved3.3 analysis certificate document supplied by the international standard instrument holder body or national standard instrument holder body containing the individual values of measurements, the mass per hectolitr
33、e average value and its uncertainty for the test sample being analysed 3.4 conformity certificate document, issued by the body in charge of verifying the performances of the instrument, specifying the conformity decision for the requested use 3.5 control chart chart on which some statistical measure
34、 of a series of samples is plotted in a particular order to steer the process with respect to that measure and to control and reduce variation ISO 3534-2:20061, 2.3.1 NOTE The analysis values are plotted on the ordinate against the date (day or hour) of carrying out the measurement on the abscissa.
35、4 Requirements 4.1 Certified international or national standard instrument A standard measurement instrument for mass per hectolitre has a 20 l hopper and is certified by a national or international authority. An informative list of such instruments is given in Annex B. 4.2 National standard instrum
36、ent Each country defines, on the basis of the specifications given in 6.2, the instrument designated as a national standard instrument within the respective country. This national standard instrument should be an instrument designated by its name (model, manufacturer, serial number). Any other instr
37、ument of the same model as that adopted as the national standard instrument shall not be referred to as a “national standard instrument”. Each country defines the public or private organization responsible for the safe keeping, use, and maintenance of this national standard instrument. This same org
38、anization ensures its traceability through reference to a certified international or national standard instrument (4.1), according to the provisions specified in 7.1, every 10 years. Each country shall ensure that no natural or legal person is refused access to the results of this national standard
39、instrument so that any manufacturer, holder, repairer, controller or user can ensure the traceability of his own instruments through reference to the national standard instrument. 4.3 Secondary or internal standard instrument For the purposes of inspection of instruments in operation, a body may pos
40、sess an appliance specific to this activity. This instrument shall have the required qualities, established using the national standard instrument. It shall then constitute the reference which ensures the traceability of the instruments in operation. Verify and adjust these secondary standard instru
41、ments every 2 years in accordance with 7.2. 4.4 Routine measuring instrument This term designates any mass per hectolitre measuring instrument used in commercial transactions. BS EN ISO 7971-2:2009ISO 7971-2:2009(E) ISO 2009 All rights reserved 3The traceability of instruments in operation and of ne
42、w instruments (prior to commissioning) shall be ensured through reference to a secondary standard instrument (4.3) according to the provisions specified in 7.3. The frequency of this traceability operation is 1 year. 5 Principle This part of ISO 7971 specifies a procedure for ensuring the traceabili
43、ty of mass per hectolitre measuring instruments through reference to standard instruments. The traceability principle is illustrated by Figure 1. Figure 1 Principle of traceability of instruments through reference to standard instruments 6 Apparatus 6.1 International standard instrument for mass per
44、 hectolitre as specified in ISO 7971-1. 6.2 National standard instrument for mass per hectolitre. Manual or automatic, mechanical, electric or electronic mass per hectolitre measuring instrument, of which the capacity of the measuring container is at least 1 l, accepting a bias correction or a bias
45、and slope correction. This instrument is used according to the requirements given in 4.2 and traceability is ensured through reference to the international standard instrument according to the procedure specified in 7.1. BS EN ISO 7971-2:2009ISO 7971-2:2009(E) 4 ISO 2009 All rights reservedThe corre
46、ction made to the instrument ensures a slope and an intercept which are not significantly different from 1 and 0 at the 5 % threshold see Equations (A.8), (A.9), and (A.10), A.7.3 and A.8.2. If the national standard instrument is a 20 l apparatus, for any correction refer to ISO 7971-1. 6.3 Secondar
47、y standard instrument for the mass per hectolitre. Manual or automatic, mechanical, electric or electronic mass per hectolitre measuring instrument, of which the capacity of the measuring container is at least 750 ml, accepting a bias and/or slope correction. This instrument is used according to the
48、 requirements given in 4.3 and traceability is ensured through reference to the national standard instrument according to the procedure specified in 7.2. The correction made to the instrument ensures a slope and an intercept which are not significantly different from 1 and 0 at the 5 % threshold see
49、 Equations (A.8), (A.9), and (A.10), A.7.3 and A.8.2. 6.4 Mass per hectolitre measuring instrument. Manual or automatic, mechanical, electric or electronic, adjustable or fixed mass per hectolitre measuring instrument, associated if necessary with an equivalence or correction table and used according to the requirements given in 4.4. The verification of these instruments specified in 7.3 concerns both new instruments and instruments in operation. The amplitude between the highest and the lowest value, i, me
