I BS ISO BRITISH STANDARD 4268:2000 ISO 4268:2000 Petroleum and liquid petroleum products D Temperature measurements D Manual methods ICS75.180.30 BS NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BS ISO 4268:2000 National foreword This British Standard reproduces verbatim IS0 4268:2000 and implements it as the UK national standard. The UKparticipation in its preparation was entrusted byTechnical Committee PTI/12, Petroleum measurement and sampling, to Subcommittee PTI/12/1, Static and dynamic petroleum measurement, which has the responsibility to: aid enquirers to understand the text; 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 theUK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referredtointhisdocumentmaybefoundintheBSIStandardsCatalogueunderthe sectionentitledalnternationalStandardsCorrespondenceIndex,orbyusingthe aFind° facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users ofBritish Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages i to vi, pages 1 to 32, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document waslastissued. This British Standard, having Amendments issued since publication been prepared under the direction of the Sector Amd. No. Date Comments CommitteeforMaterials and Chemicals, was published under the authority ofthe Standards Committeeandcomesintoeffect on 15 December 2000 @BSI 12-2000 ISBN 0 580 36770 3 ISO INTERNATIONAL STANDARD 4268 First edition 2000-09-15 Petroleum and liquid petroleum products Temperature measurements Manual methods Pétrole et produits peétroliers liquides Mesurages de la température- Méthodes manuelles Reference number ISO 4268:2000(E) ISO ISO 4268:2000(E) ii ISO 4268:2000(E) Contents Foreword, Introduction 1 Scope.. 2 Normativereferences, 3 Introduction to precautions.... 4 Precautions relating to procedures.. 5 Precautions relating to safety 5.1 Introduction... 5.2 General safety precautions. 5.3 Special safety precautions . 6 Equipment Portable electronic thermometers (PETs).. 7.1 Introduction.... 7.2 Accuracy requirements... 7.3 Sensing elements .... 7.4 Electrical safety ....... 7.5 Selection and operation of portable electronic thermometers. 8 Liquid-in-glass thermometers. 8.1 General.. 8.2 Accuracyandresolution.. 8.3 Specifications .... 8.4 General requirements for liquid-in-glass thermometers ... 8.5 Periodic checks of liquid-in-glass thermometers ... 8.6 Armouredcasesforliquid-in-glassthermometers.. 9 Precautions to be taken when selecting and using liquid-in-glass thermometers . 9.1 Selectionofthermometers... 9.2 Detection and prevention of errors in liquid-in-glass thermometers. 13 9.3 Emergent-stemcorrection.. 13 10 Tank sampling methods . 10.1 Cup-case thermometer .... 10.2 Flushing-case thermometer 10.3 Sampling-bottle methods ... 16 11 Vapour-lock samplers and associated thermometers. 11.1 Vapour-locks on pressurized tanks.... 16 11.2 Outine description.. 16 12 Permanently installed spot thermometers.. 7 12.1 Angle-stem thermometers. 17 12.2 Tank-bottom liquid-in-glass thermometers. 19 12.3 Accuracy and resolution... 19 13 Bimetal-actuated thermometer with dial 19 13.1 Introduction...... 13.2 Description.. 19 13.3 Accuracy and resolution.. 19 14 Procedures ili ISO 4268:2000(E) 15 Liquids in pressurized tanks.. .19 15.1 Introduction... 15.2 Ge