ISO INTERNATIONAL STANDARD 15970 First edition 2008-06-15 Natural gas Measurement of properties Volumetric properties: density, pressure, temperature and compression factor Gaznaturel-Mesurage des caracteristiques-Caracteristiques volumetriques:massevolumique,pression,temperatureetfacteurde compression Referencenumber ISO15970:2008(E) @ISO 2008 ISO15970:2008(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The IsO Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. COPYRIGHTPROTECTEDDOCUMENT ISO2008 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, ISO's member body in the country of the requester. ISO copyright office Case postale 56.CH-1211Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail [email protected] Web www.iso.org Published in Switzerland ii @ ISO 2008 - All rights reserved ISO15970:2008(E) Contents Page Foreword. Introduction 1 Scope. 2 Normative references 3 Terms and definitions.... 3.1 Terms and definitions for density at reference conditions 3.2 Terms and definitions for density at operating conditions.. 3.3 Terms and definitions for pressure ..... 3.4 Terms and definitions for temperature. 3.5 Termsand definitions for compression factor.... 4 Symbols and units......... 4.1 Symbols and subscripts fordensity atreference conditions 4.2 Symbols and subscripts for density at operating conditions..... 4.3 Symbolsandsubscriptsforcompressionfactor... 5 Density at reference conditions. 5.1 Principle of measurement... 5.2 Performance assessment and acceptance tests.... 10 5.3 Samplingandinstallationguidelines 11 5.4 Calibration... 11 5.5 Verification 5.6 5.7 Quality control.. 12 6 Densityatoperatingconditions 12 6.1 Principle of measurement... 12 6.2 Performance assessment and acceptance tests.... 13 6.3 Samplingand installation guidelines... 16 6.4 Calibration... 20 6.5 Verification 20 6.6 Maintenance..... 6.7 Quality control. 21 7 21 7.1 Principle of measurement... 22 7.2 Performance assessment and acceptance tests.. 24 7.3 Sampling and installation guidelines .... 7.4 Calibration... 27 7.5 Verification 28 7.6 28 7.7 Qualitycontrol. 29 8 Temperature. 8.1 Principle of measurement. 29 8.2 Performance assessmentand acceptancetests. 30 8.3 Installationguidelines 8.4 Calibration.. 33 8.5 Verification 34 8.6 Maintenance.... 8.7 Quality control.. 9 Compression factor... @ Iso 2008 -All rights reserved ili ISO15970:2008(E) 9.1 Principle ofmeasurement...... 9.2 Working principle.. .35 9.3 Performanceassessmentandacceptancetests ..38 9.4 Samplingand installationguidelines ..38 9.5 Calibration... 9.6 Verification.. ..40 9.7 Maintenance.. 40 9.8 Qualitycontrol Annex A(informative)Guidance for instrument selection, instrumenttest andoperationalprocedures... ..41 AnnexB(informative)Instrumentdocumentation. Bibliography ...47 iv ISO 2008 -All rights reserved ISO15970:2008(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 non-governmental, in liaison with IsO, also take part in the work. Iso collaborates closely ywith the InternationalElectrotechnicalCommission(lEC)onallmattersofelectrotechnicalstandardization. International Standards are drafted in accordance with the rules given in the ISO/lEc Directives, Part 2. The main task of technical committee