1、BSI Standards PublicationBS ISO 7504:2015Gas analysis VocabularyBS ISO 7504:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 7504:2015. Itsupersedes BS ISO 7504:2001 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommit
2、tee PTI/15, Natural Gas and Gas Analysis.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards In
3、stitution 2015. Published by BSI StandardsLimited 2015ISBN 978 0 580 77140 8ICS 01.040.71; 71.040.40Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 May 2015.Ame
4、ndments issued since publicationDate Text affectedBS ISO 7504:2015 ISO 2015Gas analysis VocabularyAnalyse des gaz VocabulaireINTERNATIONAL STANDARDISO7504Third edition2015-05-15Reference numberISO 7504:2015(E)BS ISO 7504:2015ISO 7504:2015(E)ii ISO 2015 All rights reservedCOPYRIGHT PROTECTED DOCUMENT
5、 ISO 2015, Published in SwitzerlandAll 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 mechanical, including photocopying, or posting on the internet or an intranet, without prior written perm
6、ission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 7504:2015ISO 7504:
7、2015(E)Foreword iv1 Scope . 12 Normative references 13 Terms relating to general concepts . 14 Terms relating to physical properties 35 Terms relating to calibration gases . 56 Terms relating to methods for the preparation of gas mixtures 67 Terms relating to storage in gas cylinders . 78 Terms rela
8、ting to gas analysis. 79 Terms from metrology 9Annex A (normative) List of terms defined in ISO/IEC Guide 98-3 and ISO/IEC Guide 99 11Annex B (normative) Sampling definitions 12Annex C (informative) Index 13Bibliography .15 ISO 2015 All rights reserved iiiContents PageBS ISO 7504:2015ISO 7504:2015(E
9、)ForewordISO (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 t
10、echnical 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 Electrotechnical Commission (IEC) on all matters
11、 of electrotechnical standardization.The procedures used 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 docume
12、nt was drafted in accordance with the editorial rules 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
13、 patent rights. Details of any patent rights identified 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
14、not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT), see the following URL: Foreword Supplementary informatio
15、n .The committee responsible for this document is ISO/TC 158, Analysis of gases.This third edition cancels and replaces the second edition (ISO 7504:2001), which has been technically revised for alignment with the terminology used in other International Standards, including ISO/IEC Guide 98-3 and IS
16、O/IEC Guide 99:2007.iv ISO 2015 All rights reservedBS ISO 7504:2015Gas analysis Vocabulary1 ScopeThis International Standard defines terms related to gas analysis, with the main focus on terms related to calibration gas mixtures for use in gas analysis and gas measurements. It does not cover terms w
17、hich relate only to specific applications.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the
18、 referenced document (including any amendments) applies.ISO/IEC Guide 98-3:2008, Uncertainty of measurement Part 3: Guide to the expression of uncertainty in measurement (GUM:1995)ISO/IEC Guide 99:2007, International vocabulary of metrology Basic and general concepts and associated terms (VIM)ISO 10
19、715:1997, Natural gas Sampling guidelines3 Terms relating to general conceptsTerms used in the field of gas analysis that are well defined by either ISO/IEC Guide 98-3 or ISO/IEC Guide 99 are included in Annex A.3.1homogeneitystate of a gas mixture wherein all of its components (3.3) are distributed
20、 uniformly throughout the volume occupied by the gas mixture3.2stabilityattribute of a gas mixture, under specified conditions, to maintain its composition (3.5) within specified uncertainty (Annex A) limits for a specified period of time (maximum storage life (7.5)3.3componentchemical entity at a d
21、efined physical state present in a material or in a mixture3.4contentamount-of-substance fraction (3.5.1.1), mass fraction (3.5.1.2), volume fraction (3.5.1.3), amount-of-substance concentration (3.5.2.1), mass concentration (3.5.2.2), volume concentration (3.5.2.3) of a component (3.3) in a gas or
22、gas mixtureNote 1 to entry: See ISO 149127for further information about this concept.EXAMPLE 1 The hydrogen content in a mixture of hydrogen and nitrogen, expressed as an amount-of-substance fraction (3.5.1.1), is x(H2) = 0,1.EXAMPLE 2 The content of sulfur dioxide in air at p = 101,325 kPa and T =
23、288,15 K, expressed as a mass concentration (3.5.2.2), is (SO2) = 1 mg/m3.INTERNATIONAL STANDARD ISO 7504:2015(E) ISO 2015 All rights reserved 1BS ISO 7504:2015ISO 7504:2015(E)3.5compositionidentity and content (3.4) of each component (3.3) that constitute a particular gas mixture3.5.1 Fractions3.5.
24、1.1amount-of-substance fractionmole fractionxB, yBquotient of the amount of substance of a component B and the sum of the amounts of substance of all components (3.3) of the gas mixtureSOURCE: ISO 80000-9:2009, 9-143.5.1.2mass fractionwBquotient of the mass of a component B and the sum of the masses
25、 of all components (3.3) of the gas mixtureSOURCE: ISO 80000-9:2009, 9-123.5.1.3volume fractionBquotient of the volume of a component B and the sum of the volumes of all components (3.3) of the gas mixture before mixing, all volumes referring to the pressure and the temperature of the gas mixtureSOU
26、RCE: ISO 80000-9:2009, 9-153.5.2 Concentrations3.5.2.1amount-of-substance concentrationmole concentrationcBquotient of the amount of substance of a component B and the volume of the gas mixtureSOURCE: ISO 80000-9:2009, 9-133.5.2.2mass concentrationBquotient of the mass of a component B and the volum
27、e of the gas mixtureSOURCE: ISO 80000-9:2009, 9-11.23.5.2.3volume concentrationBquotient of the volume of a component B before mixing and the volume of the gas mixture, both volumes referring to the same pressure and the same temperatureNote 1 to entry: The volume concentration and the volume fracti
28、on (3.5.1.3), both referring to the same pressure and the same temperature, have identical values if, and only if, the sum of the component volumes and the volume of the whole gas mixture are identical.2 ISO 2015 All rights reservedBS ISO 7504:2015ISO 7504:2015(E)4 Terms relating to physical propert
29、ies4.1equation of statemathematical relationship between the state variables (pressure and temperature) of a gas or gas mixture and the volume occupied by a given amount of substance, written as pV = ZnRTNote 1 to entry: In this relationshipp is the pressure;V is the volume;Z is the compressibility
30、factor (4.2);n is the amount of substance;R is the molar gas constant;T is the absolute temperature.4.2compressibility factorcompression factorZ-factorreal-gas factorquotient of the volume of an arbitrary amount of gas at specified pressure and temperature and the volume of the same amount of gas, a
31、t the same state conditions, as calculated from the ideal gas law4.3reference conditionsdefinite values of pressure and temperature (state conditions) of gases and gas mixtures to which the results of measurements and/or calculations should referEXAMPLE In the field of gas analysis and gas measureme
32、nt, the following conditions are commonly preferred: normal conditions: p = 101,325 kPa, T = 273,15 K; metric standard conditions: p = 101,325 kPa, T = 288,15 K (see ISO 134435).4.4densityBquotient of the mass and the volume occupied by that mass at specified state conditionsSOURCE: ISO 80000-9:2009
33、, 9-11.14.4.1relative densityquotient of the gas density and the density of dry air of standard composition, specified at the same state conditionsSOURCE: ISO 6976:1995, 2.4, modified Language aligned with other definitions4.5saturation vapour pressurepressure exerted by the vapour of a chemical sub
34、stance in equilibrium with a condensed phase (liquid or solid or both) in a closed systemNote 1 to entry: For each pure substance, saturation vapour pressure is a function of temperature only. ISO 2015 All rights reserved 3BS ISO 7504:2015ISO 7504:2015(E)4.6dew pointtemperature at or below which, at
35、 a specified pressure, condensation from the gas phase will occurNote 1 to entry: For pure substances, dew point and bubble point (4.7) coincide. At that temperature, the pressure equals the saturation vapour pressure (4.5).4.7bubble pointpressure and temperature condition at which the liquid phase
36、is in equilibrium with the first appearing bubbles of gasNote 1 to entry: For pure substances, dew point (4.6) and bubble point coincide. At that temperature, the pressure equals the saturation vapour pressure (4.5).4.8critical pointsingle point in pressure-temperature space at which the composition
37、 (3.5) and properties of the gas and liquid phases in equilibrium are identicalNote 1 to entry: The pressure at this point is known as the “critical pressure pc” and the temperature as the “critical temperature Tc”, respectively.Note 2 to entry: For a pure substance, the critical temperature is that
38、 temperature above which only the gas phase can exist irrespective of the applied pressure.4.9cricondenbarmaximum pressure at which two-phase separation (condensation) can occurNote 1 to entry: The phase coordinates cricondenbar and cricondentherm (4.10) apply to gas mixtures (with the binary system
39、 as the simplest case). For a gas mixture, the critical point (4.8) is no longer the maximum pressure, as well as the maximum temperature for vapour-liquid coexistence (see Figure 1).Note 2 to entry: It is the highest pressure in the two-phase envelope and generally higher than the critical pressure
40、.Note 3 to entry: For a pure substance, cricondentherm (4.10), cricondenbar, and critical point (4.8) are represented by a single point, i.e. the critical point.4.10cricondenthermmaximum temperature at which two-phase separation (condensation) can occurNote 1 to entry: The phase coordinates criconde
41、nbar (4.9) and cricondentherm apply to gas mixtures (with the binary system as the simplest case). For a gas mixture, the critical point (4.8) is no longer the maximum pressure, as well as the maximum temperature for vapour-liquid coexistence (see Figure 1).Note 2 to entry: It is the highest tempera
42、ture in the two-phase envelope and generally higher than the critical temperature.Note 3 to entry: For a pure substance, cricondentherm, cricondenbar (4.9), and critical point (4.8) are represented by a single point, i.e. the critical point.4 ISO 2015 All rights reservedBS ISO 7504:2015ISO 7504:2015
43、(E)Key1 critical point B dew point curve2 cricondenbar (l) liquid phase3 cricondentherm (g) gaseous phaseA bubble point curve (lg) two-phase (liquid-vapour) regionFigure 1 The p,T phase envelope of a binary system5 Terms relating to calibration gases5.1calibration gas mixturegas mixture of known sta
44、bility (3.2) and homogeneity (3.1) whose composition (3.5) is well established for use in the calibration (Annex A) or verification (9.2) of a measuring instrument or for the validation (9.3) of a measurementNote 1 to entry: Calibration gas mixtures are measurement standards (Annex A) as defined in
45、ISO/IEC Guide 99.5.2reference gas mixturecalibration gas mixture (5.1) whose composition (3.5) is well established and stable to be used as a reference standard of composition from which other composition data measurements are derivedNote 1 to entry: Reference gas mixtures are reference measurement
46、standards (Annex A) as defined in ISO/IEC Guide 99.5.3parent gasgas, vapour, or gas mixture used for preparation of other gas mixtures ISO 2015 All rights reserved 5BS ISO 7504:2015ISO 7504:2015(E)5.4complementary gasbalance gasdiluent gasmajor gasmatrix gascomponent (3.3) of a gas mixture which is
47、usually added at the completing step of the mixture preparation or used as a diluent in preparation of the mixture by dynamic method (6.4)Note 1 to entry: Generally, the particular application of the gas mixture determines the selection of the complementary gas.Note 2 to entry: The complementary gas
48、 may also be a mixture (e.g. air).5.5impurityundesired minor component (3.3) present in a parent gas (5.3) and thus detectable in a gas mixture made of this parent gas5.5.1critical impurityimpurity affecting the intended use of a gas mixtureNote 1 to entry: The criteria for a critical impurity are g
49、iven in ISO 19229.5.5.2significant impurityimpurity that is predicted to contribute more than 10 % of the target uncertainty in the final gas mixture5.6zero gasgas or gas mixture with sufficiently low content of the component(s) (3.3) of interest, used to produce the zero response (8.3.2) of a given instrument for a given range of content (3.4)6 Terms relating to methods for the preparation of gas mixtures6.1gravimetric methodmethod in which the mass of each component (3.3) present is determined by weighing6.2man
