1、 ISO 2016 Validation methods for fire gas analyses Part 2: Intralaboratory validation of quantification methods Mthode de validation des analyses de gaz dincendie Partie 2: Validation intralaboratoire des mthode de danalyse INTERNATIONAL STANDARD ISO 12828-2 First edition 2016-12-15 Reference number
2、 ISO 12828-2:2016(E) ISO 12828-2:2016(E)ii ISO 2016 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2016, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mech
3、anical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 CP 401 CH-1214 Vernier, Geneva,
4、Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.org ISO 12828-2:2016(E)Foreword iv Introduction v 1 Scope . 1 2 Normative references 1 3 Terms and definitions . 1 4 Symbols and abbreviated terms . 2 5 General considerations 2 5.1 Actual concentration and measured conc
5、entration 2 5.2 Selection of analytical methods with respect to the physical fire model used 3 5.3 Validation of analytical techniques 3 6 Sampling and measurement effectiveness 5 6.1 General considerations 5 6.2 Sampling probe . 6 6.3 Transportation of effluent from sampling probe to analysis syste
6、m . 6 6.4 Conditioning of the effluent . 7 6.5 Measurement technique . 7 7 Validation steps . 7 7.1 General . 7 7.2 Definition of the range of application and range of calibration 8 7.3 Validation of the independence from the matrix effects . 9 7.4 Validation of the specificity of the chosen method
7、9 7.4.1 General 9 7.4.2 Simple method . 9 7.4.3 Quantitative method 10 7.5 Influence of the measurement technique on results .11 7.5.1 Generalities 11 7.5.2 Simple methods .13 7.5.3 Quantitative method 13 7.6 Calibration studies 16 7.6.1 General.16 7.6.2 Analysis of calibration model using the Fishe
8、r statistic .18 7.6.3 The BIC (Bayesian Information Criterion) .18 7.6.4 Analysis of calibration model using the AICc (Corrected Akaike Information Criterion) .19 8 Determination of uncertainties .19 Annex A (informative) Example of application of validation steps: Analysis of hydrogen chloride and
9、hydrogen bromide from trapping solutions .20 Annex B (informative) Example of an uncertainty calculation: Analysis of hydrogen chloride in trapping solutions .30 Bibliography .33 ISO 2016 All rights reserved iii Contents Page ISO 12828-2:2016(E) Foreword ISO (the International Organization for Stand
10、ardization) 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 established has the right
11、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 Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. The procedures u
12、sed to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules
13、 of the ISO/IEC Directives, Part 2 (see www.iso.org/directives). 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. Details of any patent rights identif
14、ied during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement. For an explanation o
15、n the meaning of ISO specific terms and expressions related to conformit y assessment, as well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html. The committee responsible
16、 for this document is ISO/TC 92, Fire safety, Subcommittee SC 3, Fire threat to people and the environment. A list of all parts in the ISO 12828 series can be found on the ISO website.iv ISO 2016 All rights reserved ISO 12828-2:2016(E) Introduction The reduction of human tenability from fire effluen
17、t has long been recognized as a major cause of injury and death in fire. The composition and concentration of the effluent from a large fire are also clearly key factors in determining the potential for harm to the environment. The harmful components of fire effluent can be determined from both larg
18、e-and small-scale tests of materials and finished products. Equations have been developed for quantifying the effects of the effluent components, for example, to estimate the available safe egress time (ASET). Related documents are also being developed in ISO TC92 SC3 which deal with environmental t
19、hreats from fire effluent. These advances in fire science and fire safety engineering have led to an increasing demand for quantitative measurements of the chemical components of the fire effluent. Characterizing these measurements is a key factor in evaluating the quality of the quantitative data p
20、roduced. Such a characterization is developed over four items. Item 1: Define the objective of the analysis. Before undertaking a chemical analysis of fire effluent, the final objective of the analysis should be established. For example, the objective might be part of a fire safety engineering desig
21、n of a building, validation of a numerical fire model, or determination of the toxic potency of the effluent from a particular combustible item. Item 2: Determine the degree of accuracy and precision required from the analysis. Accuracy is dependent on a combination of the physical fire model being
22、used, the sampling of the effluent and the analytical chemical technique. Precision means the tolerable uncertainty in the measured result. For example, in an FED (Fractional Effective Dose) calculation, where the individual contribution of a range of different species to the overall toxic potency o
23、f a fire effluent is estimated, interest might range from concentrations which might incapacitate people of average sensitivity to the effluent, to concentrations which show negligible toxic effect over a long exposure period. Item 3: Select the appropriate chemical analytical methods, considering s
24、pecificity, i.e. the other gases present. Guidance on options for measuring a wide variety of chemical species is provided in ISO 19701 and ISO 19702. Item 4: Evaluate the suitability of the chosen method considering specificity. For chemical analyses, as with any other measurement, it is important
25、to evaluate a specific methodology for its ability to provide appropriate, sufficient, and adequate data for a particular application. This evaluation normally has to consider a range of factors, including repeatability, reproducibility, and a measurement of uncertainty, especially for laboratories
26、working under ISO 17025 rules. For fire effluent toxicity, these properties are discussed in ISO 19706. Different methods may be deemed suitable for the particular application and for consistency in the interpretation of results from these different methods, it is also important to be able to compar
27、e the validity of the analytical technique used. In the field of fire effluents, many factors can affect the trueness and the fidelity of a measurement technique. ISO 2016 All rights reserved v Validation methods for fire gas analyses Part 2: Intralaboratory validation of quantification methods 1 Sc
28、ope This document describes tools and techniques for use in validating the analysis of fire gases when an analytical method is developed in a laboratory. It complements ISO 12828-1, which deals with limits of quantification and detection. The tools and techniques described can be applied to the meas
29、urement of quantities, concentrations (molar and mass), volume fractions, and concentration or volume fraction versus time analyses. Fire effluents are often a complex matrix of chemical species, strongly dependent on the materials involved in the fire, but also dependent on fire scenario parameters
30、 (see ISO 19706). With such a wide variety of conditions, the analytical techniques available will differ in terms of the influence of the matrix on the methods and on the concentration ranges which can be measured. The analytical techniques available are likely to differ significantly in several re
31、spects, such as their sensitivity to the matrix and the range of concentrations/volume fractions which can be reliably measured. For these reasons, a unique reference analytical technique for every fire effluent of interest is, in practical terms, difficult or impossible to achieve. The tools in thi
32、s document allow verification of the reliable measurement ranges and conditions for the analysis of fire effluents, thereby enabling a comparison among various analytical techniques. Examples of existing International Standards where the information contained in this document can be used are the ana
33、lytical chemical methods in ISO 19701, ISO 19702, ISO 5660-1, and the chemical measurements in the methods discussed in ISO/TR 16312-2, ISO 16405, or their application to fire toxicity assessment using ISO 13571 and ISO 13344. NOTE 1 The variable “concentration” is used throughout this document, but
34、 it can be replaced in all places with “volume fraction” without altering the meaning. This does not apply to the Annexes. NOTE 2 Concentration can be calculated from volume fraction by multiplying by the density of the relevant gas at the relevant temperature and pressure. 2 Normative references Th
35、e following documents are referred to in the text in such a way that some or all of their content constitutes requirements 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.
36、 ISO 12828-1:2011, Validation method for fire gas analysis Part 1: Limits of detection and quantification ISO 5479, Statistical interpretation of data Tests for departure from the normal distribution 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 13
37、943, ISO 5725-1, ISO 2854, ISO 2602, ISO 13571 and the following apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: IEC Electropedia: available at http:/ /www.electropedia.org/ INTERNATIONAL ST ANDARD ISO 12828-2:2016(E) ISO 2016 All rights re
38、served 1 ISO 12828-2:2016(E) ISO Online browsing platform: available at https:/ /www.iso.org/obp/ 3.1 matrix (of fire effluents) mixture of fire effluents in which the analyte of interest is present Note 1 to entry: This includes all other species, solid, liquid and gas phases. It constitutes all co
39、mponents that could affect analysis, such as interfering species. 4 Symbols and abbreviated terms y 0 Actual concentration of an analyte in a fire effluent y 1 Concentration just after extraction by the sampling probe y 2 Concentration after transportation to the conditioning system y 3 Concentratio
40、n at the entrance of the sensor y 4 Concentration read by the sensing apparatus X 1= y 0 /y 1 Sampling ratio; Because of the effectiveness of the sampling probe, X 1might be more than 1 (see 6.2 for details) X 2= y 1 /y 2 Transportation ratio (see 6.3 for details) X 3 = y 2 /y 3 Conditioning ratio;
41、X 3might be more than 1 (see 6.4 for details) X 4 = y 3 /y 4 Analysis ratio; X 4might be more than 1 (see 6.5 for details) y m Reported concentration of an analyte in the gas phase y i One of a number of y mvalues in a group b 0 Zero order coefficient term in a regression; For a linear regression, b
42、 0 is the intercept b 1 First order coefficient term in a regression; For a linear regression, b 1is the slope b 2 Second order coefficient term in a regression. Predicted value for y i , given by application of a regression model Mean value for y i p Total number of measurements df Degrees of freed
43、om; According to the context, several degrees of freedom could be defined SCE Sum of squares of deviations between measured values y iand mean value MS Median square, corresponding to SCE divided by df 5 General considerations 5.1 Actual concentration and measured concentration The objective of ever
44、y chemical analysis used in fire science is to approach the actual concentration of an analyte, y 0 , in fire effluents. The value of y 0is unknown, as the only value measured is the concentration 2 ISO 2016 All rights reserved ISO 12828-2:2016(E) y m . The concentration y mis affected by the measur
45、ement trueness and precision (uncertainty) of the chosen analytical technique The difference between y 0and y mcould be significant, depending as it does, on the measurement technique chosen. For fire gas analyses, there could be many alternative analytical techniques available, (see ISO 19701 and I
46、SO 19702 for examples). Stages of the analytical procedure which could affect the measurement are sampling (e.g. probe design and temperature), transportation (e.g. size, length and temperature of sampling lines), conditioning of sample (e.g. filtration, drying), and the analysis efficiency. This la
47、st factor could be integrated in the trueness of the analytical technique. The different steps of this analytical process of fire effluents and the associated efficiencies are presented in Figure 1. y m = X 1 . X 2 . X 3 . X 4 . y 0 y 0 X 1 X 2 X 3 X 4 l l Figure 1 Measurement ratios 5.2 Selection o
48、f analytical methods with respect to the physical fire model used The selection of a physical fire model has an influence on the composition of the effluent, the concentration of individual components in the effluent and variations of effluent concentration with time. These parameters imply that the
49、 choice of an analytical method for fire effluents will depend on the physical fire model that produced the effluent. An analytical method validated by using a given physical fire model may therefore be of limited use with another physical fire model. See ISO 19706 and ISO 16312-1 for further details on the selection of physical fire models. 5.3 Validation of analytical techniques Fire effluent from accidental fires is typically very specific matrix, characterized by a constantly changing and very wide range of chemical species a
