ISO INTERNATIONAL STANDARD 4266-6 First edition 2002-11-15 Petroleum and liquid petroleum products - Measurement of level and temperature in storage tanks by automatic methods Part 6: Measurement of temperature in pressurized storage tanks (non-refrigerated) Pétrole et produits pétroliers liquides-Mesurage du niveau etde la temperature danslesreservoirs de stockageparmethodes automatiques- Partie 6:Mesurage de la temperature dans les reservoirs de stockage sous pression (non refrigeres) Reference number ISO 4266-6:2002(E) ISO @ISO 2002 ISO4266-6:2002(E) PDFdisclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In 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 parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by IsO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. ISO2002 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, 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.ch Printed in Switzerland ii ISO 2002 -All rights reserved ISO 4266-6:2002(E) Contents Page 1 Scope 1 2 Normative reference 3 Terms and definitions Precautions 2 Safety precautions 2 4.2 Equipmentprecautions 2 4.3 General precautions 2 5Accuracy 3 5.1 General 3 5.2 Intrinsic error of ATTs 3 5.3 Calibration prior to installation 3 5.3.1 3 General 5.3.2 ATTcalibratedasa system 3 5.3.3 ATT calibrated by components 5.3.4 Multiple-point ATTs 4 5.3.5 Uncertainty of the reference .. 4 5.4 Error caused by installation and operating conditions Overall accuracy. 4 5.5.1 General ... 4 5.5.2 Use of ATT for fiscal/custody transfer purposes 4 6SelectionofATTs 5 6.1 General 5 6.2ATTs forfiscal/custodytransferpurpose 5 Description of ATT equipment 5 7.1 Introduction.. 5 7.2 Electricaltemperatureelements 6 7.2.1 Resistance temperaturedetectors .... 6 7.2.2 Other temperature elements .. 6 8InstallationofATTs 6 8.1 General .. 6 8.2 Single-point (spot) temperature elements 6 8.3 Multiple-point temperature elements 6 8.4 Moveablespottemperatureelement 7 8.5 Other methods .. 7 8.6Thermowellsforelectronictemperatureelements 7 8.7Thermowells forverificationpurposes 7 9 Calibration and field verification of ATTs 7 9.1 Introduction. 7 9.2 Calibration of single-point temperature element ATTs used for fiscal/custody transfer purpose 8 @ ISO 2002 - All rights reserved ili ISO 4266-6:2002(E) 9.2.1 Calibration prior to installation 8 9.2.2 Initial field verification 8 9.3 Calibration of upper, middle and lower or multiple-point ATTs 9 9.3.1Calibration priorto installation 9 9.3.2 Initial field verification 9 9.4Subsequent verification of ATTs 10 9.4.1 General 10 9.4.2 Frequencyof subsequentverification 10 9.4.3 3Record keeping . 10 10 Data communication and receiving 10 Bibliography.... 11 iv @ ISO 2002 - All rights reserved ISO4266-6:2002(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 ISsO technical committees.Eachmemberbodyinterestedinasubjectforwhichatechnicalcommitteehasbeenestablishedhas liaison with IsO, also take part in the work. Is