ISO INTERNATIONAL STANDARD 15796 First edition 2005-03-01 Gas analysis Investigation and treatment of analytical bias Analyse des gaz Investigation et traitement des biais analytiques Reference number ISO 15796:2005(E) @ISO2005 py IHS under lic ted without license from IHS Not for Resale, 12/19/2015 18:41:52 MST ISO 15796:2005(E) Contents Page Foreword Introduction 1 Scope 2 Terms and definitions. 3 Symbols 4 Bias related to instrumental drift. 4.1 Principle ... 4.2 Stability monitoring 4.3 Drift correction .. 5 Bias related to effects of sample composition .... 5.1 Principles... 10 5.2 Local bias handling... 5.3 Bias handling for an extended measuring range 23 6 Treatment of matrix interferences .. 27 Annex A (normative) Critical values for the trend test. .29 AnnexB(informative)Uncertaintyissues 30 Bibliography 33 Copyright International Organization for Stadardizaon'ghts reserved ili ut license from IHS Not for Resale, 12/19/2015 18:41:52 MST ISO 15796:2005(E) Foreword 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 interested in a subject for which a technical committee has been non-governmental, in liaison with isO, also take part in the work. iso collaborates closely with the InternationalElectrotechnicalCommission(iEC)onallmattersofelectrotechnicalstandardization. International Standards are drafted in accordance with the rules given in the ISO/lEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International 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 subject of patent rights. IsO shall not be held responsible for identifying any or all such patent rights. ISO 15796 was prepared by Technical Committee ISO/TC 158, Analysis of gases. @ISO2005-All rights reserved onal Organization for Standardizatior ISO 15796:2005(E) Introduction Traceability is considered as one of the key items of quality assurance in gas analysis. In general, it is defined uncertainty of the result. As a rule, traceability is not demonstrated individually for a single analytical result but for a defined analytical considered traceable if it has been demonstrated to be free of significant bias, or if significant bias has been in parallel using an accepted reference procedure. This International Standard provides generic methods for demonstrating, or establishing, traceability of analytical procedures using referencegas mixtures or reference analytical procedures, implementing principles laid out in ISO 14111 [1] and ISO/TS 14167 [2], and respecting the principles of the Guide to the Expression of Uncertainty in Measurement (GUM) [3]. In this International Standard, the term “concentration" is used for two different purposes: ISO 7504 [4]); the mass concentration or the mole fraction of a specified analyte (see Iso 7504 [4]) aaniar anadizatin networking pemited without license from HS Not for Resale, 12/19/2015 18:41:52 MST INTERNATIONAL STANDARD ISO15796:2005(E) Gas analysis Investigation and treatment of analytical bias 1 Scope This International Standard specifies generic methods for detecting and correcting bias (systematic errors) oi analytical procedures for the analysis of gases, using reference gas mixtures or reference analytical procedures, as well as for estimating the correction uncertainty. The main sources of (and parameters affecting) bias of analytical procedures are instrumental drift (time) and matrix interferences (matrix composition). Moreover, bias normally varies with analyte concentration. This International Standard th