1、BSI Standards Publication BS ISO 7504:2015 Gas analysis VocabularyBS ISO 7504:2015 BRITISH STANDARD National foreword This British Standard is the UK implementation of ISO 7504:2015. It supersedes BS ISO 7504:2001 which is withdrawn. The UK participation in its preparation was entrusted to Technical
2、 Committee PTI/15, Natural Gas and Gas Analysis. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British
3、Standards Institution 2015. Published by BSI Standards Limited 2015 ISBN 978 0 580 77140 8 ICS 01.040.71; 71.040.40 Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard was published under the authority of the Standards Policy and Strategy Committee
4、 on 31 May 2015. Amendments issued since publication Date Text affectedBS ISO 7504:2015 ISO 2015 Gas analysis Vocabulary Analyse des gaz Vocabulaire INTERNATIONAL STANDARD ISO 7504 Third edition 2015-05-15 Reference number ISO 7504:2015(E)BS ISO 7504:2015ISO 7504:2015(E)ii ISO 2015 All rights reserv
5、ed COPYRIGHT PROTECTED DOCUMENT ISO 2015, 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 mechanical, including photocopying, or posting on the internet or an intr
6、anet, 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, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.o
7、rg www.iso.orgBS ISO 7504:2015ISO 7504:2015(E)Foreword iv 1 Scope . 1 2 Normative references 1 3 Terms relating to general concepts . 1 4 Terms relating to physical properties 3 5 Terms relating to calibration gases . 5 6 Terms relating to methods for the preparation of gas mixtures 6 7 Terms relati
8、ng to storage in gas cylinders . 7 8 Terms relating to gas analysis. 7 9 Terms from metrology 9 Annex A (normative) List of terms defined in ISO/IEC Guide 98-3 and ISO/IEC Guide 99 11 Annex B (normative) Sampling definitions 12 Annex C (informative) Index 13 Bibliography .15 ISO 2015 All rights rese
9、rved iii Contents PageBS ISO 7504:2015ISO 7504:2015(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.
10、 Each member body interested 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 Interna
11、tional Electrotechnical Commission (IEC) on all matters 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 diffe
12、rent types of ISO documents should be noted. This document 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 shal
13、l not be held responsible for identifying any or all such 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 i
14、s information given for the convenience of users and does 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
15、), see the following URL: Foreword Supplementary information. 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
16、International Standards, including ISO/IEC Guide 98-3 and ISO/IEC Guide 99:2007.iv ISO 2015 All rights reservedBS ISO 7504:2015Gas analysis Vocabulary 1 Scope This International Standard defines terms related to gas analysis, with the main focus on terms related to calibration gas mixtures for use i
17、n gas analysis and gas measurements. It does not cover terms which relate only to specific applications. 2 Normative references The 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
18、cited applies. For undated references, the latest edition of the 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 met
19、rology Basic and general concepts and associated terms (VIM) ISO 10715:1997, Natural gas Sampling guidelines 3 Terms relating to general concepts Terms 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. 3.1 homogeneity st
20、ate of a gas mixture wherein all of its components (3.3) are distributed uniformly throughout the volume occupied by the gas mixture 3.2 stability attribute of a gas mixture, under specified conditions, to maintain its composition (3.5) within specified uncertainty (Annex A) limits for a specified p
21、eriod of time (maximum storage life (7.5) 3.3 component chemical entity at a defined physical state present in a material or in a mixture 3.4 content amount-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 concent
22、ration (3.5.2.2), volume concentration (3.5.2.3) of a component (3.3) in a gas or gas mixture Note 1 to entry: See ISO 14912 7for 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
23、(H 2 ) = 0,1. EXAMPLE 2 The content of sulfur dioxide in air at p = 101,325 kPa and T = 288,15 K, expressed as a mass concentration (3.5.2.2), is (SO 2 ) = 1 mg/m 3. INTERNATIONAL ST ANDARD ISO 7504:2015(E) ISO 2015 All rights reserved 1BS ISO 7504:2015ISO 7504:2015(E) 3.5 composition identity and c
24、ontent (3.4) of each component (3.3) that constitute a particular gas mixture 3.5.1 Fractions 3.5.1.1 amount-of-substance fraction mole fraction x B , y B quotient 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 mixture SOURCE: I
25、SO 80000-9:2009, 9-14 3.5.1.2 mass fraction w B quotient of the mass of a component B and the sum of the masses of all components (3.3) of the gas mixture SOURCE: ISO 80000-9:2009, 9-12 3.5.1.3 volume fraction B quotient of the volume of a component B and the sum of the volumes of all components (3.
26、3) of the gas mixture before mixing, all volumes referring to the pressure and the temperature of the gas mixture SOURCE: ISO 80000-9:2009, 9-15 3.5.2 Concentrations 3.5.2.1 amount-of-substance concentration mole concentration c B quotient of the amount of substance of a component B and the volume o
27、f the gas mixture SOURCE: ISO 80000-9:2009, 9-13 3.5.2.2 mass concentration B quotient of the mass of a component B and the volume of the gas mixture SOURCE: ISO 80000-9:2009, 9-11.2 3.5.2.3 volume concentration B quotient of the volume of a component B before mixing and the volume of the gas mixtur
28、e, both volumes referring to the same pressure and the same temperature Note 1 to entry: The volume concentration and the volume fraction (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
29、 the whole gas mixture are identical.2 ISO 2015 All rights reservedBS ISO 7504:2015ISO 7504:2015(E) 4 Terms relating to physical properties 4.1 equation of state mathematical relationship between the state variables (pressure and temperature) of a gas or gas mixture and the volume occupied by a give
30、n amount of substance, written as pV = ZnRT Note 1 to entry: In this relationshipp is the pressure;V is the volume;Z is the compressibility factor (4.2);n is the amount of substance;R is the molar gas constant;T is the absolute temperature. 4.2 compressibility factor compression factor Z-factor real
31、-gas factor quotient of the volume of an arbitrary amount of gas at specified pressure and temperature and the volume of the same amount of gas, at the same state conditions, as calculated from the ideal gas law 4.3 reference conditions definite values of pressure and temperature (state conditions)
32、of gases and gas mixtures to which the results of measurements and/or calculations should refer EXAMPLE In the field of gas analysis and gas measurement, the following conditions are commonly preferred: normal conditions: p = 101,325 kPa, T = 273,15 K; metric standard conditions: p = 101,325 kPa, T
33、= 288,15 K (see ISO 13443 5 ). 4.4 density B quotient of the mass and the volume occupied by that mass at specified state conditions SOURCE: ISO 80000-9:2009, 9-11.1 4.4.1 relative density quotient of the gas density and the density of dry air of standard composition, specified at the same state con
34、ditions SOURCE: ISO 6976:1995, 2.4, modified Language aligned with other definitions 4.5 saturation vapour pressure pressure exerted by the vapour of a chemical substance in equilibrium with a condensed phase (liquid or solid or both) in a closed system Note 1 to entry: For each pure substance, satu
35、ration vapour pressure is a function of temperature only. ISO 2015 All rights reserved 3BS ISO 7504:2015ISO 7504:2015(E) 4.6 dew point temperature at or below which, at a specified pressure, condensation from the gas phase will occur Note 1 to entry: For pure substances, dew point and bubble point (
36、4.7) coincide. At that temperature, the pressure equals the saturation vapour pressure (4.5). 4.7 bubble point pressure and temperature condition at which the liquid phase is in equilibrium with the first appearing bubbles of gas Note 1 to entry: For pure substances, dew point (4.6) and bubble point
37、 coincide. At that temperature, the pressure equals the saturation vapour pressure (4.5). 4.8 critical point single point in pressure-temperature space at which the composition (3.5) and properties of the gas and liquid phases in equilibrium are identical Note 1 to entry: The pressure at this point
38、is known as the “critical pressure p c ” and the temperature as the “critical temperature T c ”, respectively. Note 2 to entry: For a pure substance, the critical temperature is that temperature above which only the gas phase can exist irrespective of the applied pressure. 4.9 cricondenbar maximum p
39、ressure at which two-phase separation (condensation) can occur Note 1 to entry: The phase coordinates cricondenbar and cricondentherm (4.10) 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
40、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. Note 3 to entry: For a pure substance, cricondentherm (4.10), cricondenbar, and critical point (4.8) are repres
41、ented by a single point, i.e. the critical point. 4.10 cricondentherm maximum temperature at which two-phase separation (condensation) can occur Note 1 to entry: The phase coordinates cricondenbar (4.9) and cricondentherm apply to gas mixtures (with the binary system as the simplest case). For a gas
42、 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 temperature in the two-phase envelope and generally higher than the critical temperature. Note 3 to entry: For a p
43、ure 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(E) Key 1 critical point B dew point curve 2 cricondenbar (l) liquid phase 3 cricondentherm (g) gaseous ph
44、ase A bubble point curve (lg) two-phase (liquid-vapour) region Figure 1 The p,T phase envelope of a binary system 5 Terms relating to calibration gases 5.1 calibration gas mixture gas mixture of known stability (3.2) and homogeneity (3.1) whose composition (3.5) is well established for use in the ca
45、libration (Annex A) or verification (9.2) of a measuring instrument or for the validation (9.3) of a measurement Note 1 to entry: Calibration gas mixtures are measurement standards (Annex A) as defined in ISO/IEC Guide 99. 5.2 reference gas mixture calibration gas mixture (5.1) whose composition (3.
46、5) is well established and stable to be used as a reference standard of composition from which other composition data measurements are derived Note 1 to entry: Reference gas mixtures are reference measurement standards (Annex A) as defined in ISO/IEC Guide 99. 5.3 parent gas gas, vapour, or gas mixt
47、ure used for preparation of other gas mixtures ISO 2015 All rights reserved 5BS ISO 7504:2015ISO 7504:2015(E) 5.4 complementary gas balance gas diluent gas major gas matrix gas component (3.3) of a gas mixture which is usually added at the completing step of the mixture preparation or used as a dilu
48、ent 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 may also be a mixture (e.g. air). 5.5 impurity undesired minor component (3.3)
49、 present in a parent gas (5.3) and thus detectable in a gas mixture made of this parent gas 5.5.1 critical impurity impurity affecting the intended use of a gas mixture Note 1 to entry: The criteria for a critical impurity are given in ISO 19229. 5.5.2 significant impurity impurity that is predicted to contribute more than 10 % of the target uncertainty in the final gas mixture 5.6 zero gas gas or gas mixture with sufficiently low content of the component(s) (3.3) of interest, used to produce the zero
