ISO INTERNATIONAL STANDARD 8196-2 IDF 128-2 Second edition 2009-10-01 Milk Definition and evaluation of the overall accuracy of alternative methods of milk analysis - Part 2: Calibration and quality control in the dairy laboratory Lait Définition et évaluation de la precision globale des méthodes alternatives d'analyse du lait- Partie 2: Calibrage et controle qualite dans les laboratoires laitiers Reference numbers ISO 8196-2:2009(E) IDF 128-2:2009(E) @ ISO and IDF 2009 ISO 8196-2:2009(E) IDF128-2:2009(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. Neither the ISo Central Secretariat nor the IDF accepts any liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by IsO member bodies and IDF national committees. In the unlikely event that a problem relating to it is found, please inform the ISO Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT @ ISO and IDF 2009 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, address below. ISO copyright office International Dairy Federation Case postale 56 . CH-1211 Geneva 20 Diamant Building · Boulevard Auguste Reyers 80 · B-1030 Brussels Tel. + 41 22 749 01 11 Tel. + 32 2 733 98 88 Fax + 41 22 749 09 47 Fax + 32 2 733 04 13 E-mail copyright@iso.org E-mail info@fil-idf.org Web www.iso.org Web www.fil-idf.org Published in Switzerland ii @ ISO and IDF 2009 - All rights reserved ISO 8196-2:2009(E) IDF 128-2:2009(E) Contents Page Foreword. .iv Foreword Introduction. 1 Scope. 2 Normative references. 3 Terms, definitions, and symbols .. 3.1 Terms and definitions .. 3.2 Symbols..... 4 Calibration of instruments.. 4.1 General principles .... 4.2 General procedure.. 4.3 Frequency of calibration control 0 4.4 Centralized calibration............... 11 5 Quality control in a routine dairy laboratory . 11 5.1 Verification of repeatability .. 11 5.2 Daily check on short-term stability of the instrument ... 11 5.3 Verification of bias between laboratories .... 14 5.4 Verification of the difference between reference and alternative method results....... 5.5 Verification of the compliance of alternative method results with a compositional requirement.......... .16 6 Examples... 18 6.1 Calculation of statistical values. .18 6.2 Determination of repeatability... 20 6.3 Verification of the exactness of the calibration ... 20 6.4 Determination of accuracy ....... 22 6.5 Checking the difference between reference and alternative method results 22 6.6 Conclusions ... 22 6.7 Verification of compliance with target values and upper or lower limits .... 23 Bibliography.. 25 @ ISO and IDF 2009 - All rights reserved ii