1、BRITISH STANDARD BS ISO 8573-5:2001 Compressed air Part 5: Test methods for oil vapour and organic solvent content ICS 71.100.20; 23.140 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS ISO 8573-5:2001 This British Standard, having been prepared under the direction of the Eng
2、ineering Sector Policy and Strategy Committee title here, was published under the authority of the Standards Policy and Strategy Committee on 1 March 2002 BSI 1 March 2002 ISBN 0 580 39039 X National foreword This British Standard reproduces verbatim ISO 8573-5:2001 and implements it as the UK natio
3、nal standard. The UK participation in its preparation was entrusted to Technical Committee MCE/8, Compressors, pneumatic tools, pneumatic machines and vacuum technology, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary
4、. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Cata
5、logue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the te
6、xt; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front co
7、ver, an inside front cover, the ISO title page, pages ii to iv, pages 1 to 11 and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date Comments Reference number ISO 8573-5:2001(E) ISO1002 INTERN
8、ATIONAL STANDARD ISO 8573-5 First edition 2001-12-15 Compressed air Part 5: Test methods for oil vapour and organic solvent content Air comprim Partie 5: Mthodes dessai pour la teneur en vapeurs dhuile et en solvants organiques ii ISO 8573-5:2001(E) iiiContents Page Foreword.iv 1 Scope1 2 Normative
9、references1 3 Terms and definitions .2 4 Oil vapour classes.2 5 Test methods.2 6 Sampling.2 7 Measurement3 8 Evaluation of test results4 9 Uncertainty.4 10 Test report5 Annex A (normative) Test procedures7 Annex B (informative) Daltons law of partial pressure 10 Bibliography11 ISO 8573-5:2001(E) iv
10、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 t
11、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
12、 of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulate
13、d 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 part of ISO 8573 may be the subject of patent rights. ISO shall not be held resp
14、onsible for identifying any or all such patent rights. International Standard ISO 8573-5 was prepared by Technical Committee ISO/TC 118, Compressors, pneumatic tools and pneumatic machines, Subcommittee SC 4, Quality of compressed air. ISO 8573 consists of the following parts, under the general titl
15、e Compressed air: Part 1: Contaminants and purity classes Part 2: Test methods for aerosol oil content Part 3: Test methods for measurement of humidity Part 4: Test methods for solid particle content Part 5: Test methods for oil vapour and organic solvent content Part 6: Test methods for gaseous con
16、taminant content Part 7: Test methods for viable micro biological contaminant content The following parts are under preparation: Part 8: Test methods for solid particle content by mass concentration Part 9: Test methods for liquid water content Annex A forms a normative part of this part of ISO 8573
17、. Annex B is for information only. INTERNATIONAL STANDARD ISO 8573-5:2001(E)1Compressed air Part 5: Test methods for oil vapour and organic solvent content 1 Scope This part of ISO 8573 specifies the gas chromatography test method for determining the content of oil vapour (hydrocarbons of six or mor
18、e carbon atoms) in compressed air, regardless of the source of the compressed air, as well as of any organic solvents in the vapour, difficult to separate from the other hydrocarbons. It also gives guidelines on the use of chemical indicator tubes as an initial indication of the presence of oil vapo
19、ur. This part of ISO 8573 elaborates sampling, measurement, evaluation, uncertainty considerations and reporting in respect of the compressed air purity class parameter, oil vapour, in accordance with ISO 8573-1. NOTE Lighter hydrocarbons composed of five or less carbon atoms are dealt with as gaseo
20、us contaminants in 8573-6. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this part of ISO 8573. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. Howev
21、er, parties to agreements based on this part of ISO 8573 are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC mai
22、ntain registers of currently valid International Standards. ISO 2591-1, Test sieving Part 1: Methods using test sieves of woven wire cloth and perforated metal plate ISO 3857-1, Compressors, pneumatic tools and machines Vocabulary Part 1: General ISO 5598, Fluid power systems and components Vocabula
23、ry ISO 8573-1:2001, Compressed air Part 1: Contaminants and purity classes ISO 8573-2:1996, Compressed air for general use Part 2: Test methods for aerosol oil content ISO 8573-3, Compressed air Part 3: Test methods for measurement of humidity ISO 9486, Workplace air Determination of vaporous chlori
24、nated hydrocarbons Charcoal tube/solvent desorption/gas chromatographic method ISO 9487, Workplace air Determination of vaporous aromatic hydrocarbons Charcoal tube/solvent desorption/gas chromatographic method ISO 8573-5:2001(E) 2 3 Terms and definitions For the purposes of this part of ISO 8573, t
25、he terms and definitions given in ISO 3857-1, ISO 5598 and ISO 8573-1, and the following apply. 3.1 mesh indication of particle size resulting from the grading of solids by the use of sieves with defined hole sizes 3.2 oil mixture of hydrocarbons composed of six or more carbon atoms (C 6 ) 3.3 organ
26、ic solvent mixture of one or a combination of the following identified groups: alcohols, halogenic hydrocarbons, esters, esters/etheralcohols, ketones, aromatic/alfatic hydrocarbons NOTE These compounds are characterized by a considerable vapour pressure under given conditions, when air samples are
27、analysed. 4 Oil vapour classes Oil vapour is included in the total oil concentration figure used for classification in Table 4 of ISO 8573-1:2001. 5 Test methods Selection of the available test methods depends on the range of oil vapour content in the compressed air. Gas chromatography (see clause A
28、.1) is applicable for oil vapour content in the range 0,001 mg/m 3to 10 mg/m 3 . Chemical indicator tubes (see clause A.2) are to be used as a preliminary method only, for checking purposes and as an initial investigation, after which the gas chromatography method shall be employed. 6 Sampling 6.1 G
29、eneral The quantification of the oil vapour content in a compressed air system shall be carried out within the following constraints. The sample shall be free from interfering contaminants, for example, water vapour, oil aerosol. The sampling and analysis of the oil vapour shall be performed using a
30、 constant flow rate. Air flow is normally diverted through the test equipment via suitable in-line valves. These shall have been checked to ensure they do not contribute to the level of contamination already present. Particular attention shall be given to the cleanliness of the test equipment, and o
31、ther precautions shall be taken, for example, valve purging and stabilization to constant test conditions. Good analytical techniques help improve the confidence level of the measurements. Flow measurement is required to determine the volume of air used during the test, regardless of the method. ISO
32、 8573-5:2001(E) 3The temperature and velocity range shall be within the ranges specified by the manufacturer of the test equipment. See clause A.1 for the sampling procedure. 6.2 Extraction The probe shall be installed in a small extraction tube, which conducts an air sample from the main pipe into
33、the measurement chamber, where the measurement shall be made under system pressure. 6.3 Sampling and measurement conditions 6.3.1 Repeatability Depending on the repeatability of the method and the experience of the parties involved in the provision of measurement facilities, a number of sequential m
34、easurements may need to be carried out. 6.3.2 Sampling system Materials used for conducting the air in the sampling system shall not affect the oil vapour content of the sample. The sampling system pressure shall be recorded during measurement. The sampling system temperature shall be higher than th
35、e prevailing dew-point and shall be recorded during measurement (see ISO 8573-3). 6.3.3 Measurement system The compressed air system and sampling system shall have reached a steady state before any measurement is carried out and shall be kept steady during measurement. The readings from two consecut
36、ive measurements, having between them an interval of at least 20 minutes, may not differ by more than is implied by the accuracy of the measuring system. 6.3.4 Test equipment The general arrangement of the test equipment for extracting a sample shall be as shown in Figure A.1. It is important that t
37、he test equipment not affect the collected sample. Precautions shall be taken to ensure there is no temperature drop between the compressed air system and the collection point. Practical procedures as identified in ISO 8573-2 should also be considered. 7 Measurement Consideration shall be given to t
38、he calibration requirements of the measurement equipment used, as described in applicable instructions, and to the degree of vapour concentration being measured. The requirements on equipment handling, measurement and evaluation shall be according to Method B2 of ISO 8573-2:1996. See clause A.1 for
39、specification of the gas chromatography test procedure. Prepare for measurement by cleaning and degreasing the measuring and stainless steel tubes with a solvent that does not add to the overall hydrocarbon content of the sample. Before measuring, flush the sample point and the stainless steel tube
40、up to the membrane filter with compressed air from the system, for example, for 5 min. Reference should be made to ISO 9486 and ISO 9487 with regard to methodology. ISO 8573-5:2001(E) 4 Check the standard reference conditions for the flow meter. 8 Evaluation of test results 8.1 Reference conditions
41、Unless otherwise agreed, the reference conditions for oil vapour concentration statements shall be the following. Compressed air temperature: 20 C. Compressed air: 1 bar 1)absolute. Relative water vapour pressure: 0. 8.2 Influence of humidity The humidity shall be less than 75 % and within the limit
42、s of the measurement equipment as declared by the equipment manufacturer. The appropriate calibration procedure for the measurement, as given in the manufacturers literature, should be followed. 8.3 Influence of pressure and temperature Oil vapour concentration shall be recalculated to reference pre
43、ssure conditions using the following formula: ref test ref test test ref pt cc pt = where c ref concentration at reference conditions; c test concentration at test conditions; p ref reference pressure (absolute); p test test pressure (absolute); t ref reference temperature (absolute); t test test te
44、mperature (absolute). The volume flow rate of the air is influenced by temperature. See annex B. 9 Uncertainty NOTE A calculation of the probable error according to this clause is not always necessary. Due to the very nature of physical measurements, it is impossible to measure a physical quantity w
45、ithout error or, in fact, to determine the true error of any one particular measurement. However, if the conditions of the measurement are sufficiently well-known, it is possible to estimate or calculate a characteristic deviation of the measured value 1) 1 bar = 0,1 MPa = 10 5 Pa; 1 MPa = 1 N/mm 2I
46、SO 8573-5:2001(E) 5from the true value, such that it can be asserted with a certain degree of confidence that the true error is less than the said deviation. The value of such a deviation (normally 95 % confidence limit) constitutes a criterion of the accuracy of the particular measurement. It is as
47、sumed that all systematic errors that may occur in the measurement of the individual quantities, and of the characteristics of the air, may be compensated for by corrections. A further assumption is that the confidence limits in errors in reading and integration errors may be negligible if the numbe
48、r of readings is sufficient. The (small) systematic errors that may occur are covered by the inaccuracy of measurements. Quality classifications and limits of error are often invoked for ascertaining the uncertainty of individual measurement because, apart from the exceptions (e.g. electrical transd
49、ucers), they constitute only a fraction of the quality class or the limit of error. The information about ascertaining the uncertainty of the measurement of the individual quantities measured and on the confidence limits of the gas properties are approximations. These approximations can only be improved at a disproportionate expense. See ISO 2602 and ISO 2854. 10 Test report 10.1 Statements Statements of the oil vapour or organic solvent content in the compressed air, or both, shall only be used in conjunction with s
