ISO/TR TECHNICAL REPORT 12148 First edition 2009-02-15 Natural gas Calibration of chilled mirror type instruments for hydrocarbon dewpoint (liquid formation) Gaz naturel Etalonnage des instruments du type a miroir refroidi pour points de rosée hydrocarbures (formation de liquide) Reference number ISO/TR 12148:2009(E) @ ISO 2009 by IHS under lic Not for Resale ISO/TR 12148:2009(E) Contents Page Foreword Introduction 1 Scope 2 Normative references 3 Terms and definitions. 4 Symbols. 2 5 Performance characteristics of automatic weighing method in accordance with ISO6570:2001.. 5.1 Working principle.. 5.2 Functional requirements .... 5.3 Measurement uncertainty 6 Performance requirements for a chilled-mirror-type instrument for hydrocarbon-dew point determination. 6.1 Working principle... 6.2 Precision..... Requirements/Points of interest to carry out a calibration ... 7.1 Processgas.. 8 7.2 Sampling system .. 7.3 Selection of the PHLC reference value. 7.4 Compositional range of gases covered by the calibration procedure.. 10 7.5 Calibration interval . 10 8 Execution of calibration procedure .. 8.1 General..... 10 8.2 MethodA Changeintrippointvalue..... 8.3 Method B Direct change of dew point value ... 12 8.4 Which method should be used? .... Annex A (informative) Condensation behaviour of natural gas . 13 Annex B (informative) Example of a hydrocarbon-dew-point analysis .... .16 AnnexC(informative)Examplesofacalibration.. .19 Annex D (informative) Performance of different types of chilled-mirror instruments for hydrocarbon dew point determination .... 29 Bibliography. 31 CopyrightInenationalOganzaadardizaoghtsreseved ii put license from IHS Not for Resale ISO/TR 12148:2009(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 technicalcommittees.Eachmemberbodyinterestedinasubjectforwhichatechnicalcommitteehasbeer InternationalElectrotechnicalCommission(iEC)onallmattersofelectrotechnicalstandardization. International Standards are drafted in accordance with the rules given in the ISO/lEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. In exceptional circumstances, when a technical committee has collected data of a different kind from that informative in nature and does not have to be reviewed until the data it provides are considered to be no longervalidoruseful 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. ofnaturalgas. Is0 2009 - All rights reserved ionalOrganizationfor Standardizatior