ISO INTERNATIONAL STANDARD 4262 Second edition 1993-09-15 Petroleum products Determination of carbon residue - Ramsbottom method Produits pétroliers -Détermination du résidu de carbone -Méthode Ramsbottom ISO Reference number ISO4262:1993(E) ISO 4262:1993(E) Foreword IsO (the International Organization for Standardization) is a worldwide of preparing International Standards is normally carried out through IsO technicalcommittees.Eachmemberbodyinterestedinasubjectfor which a technical 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 of electrotechnical standardization. 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. International Standard ISO 4262 was prepared by Technical Committee ISO/TC 28, Petroleum products and lubricants. This secondeditioncancelsand replaces the first edition (isO 4262:1978),whichhasbeentechnicallyrevised. Annex A forms an integral part of this International Standard. Annex B is for information only. ISO1993 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means,electronic or mechanical, including photocopying and microfilm,without per- mission in writing from the publisher. International Organization for Standardization CasePostale56·CH-1211Geneve20·Switzerland Printed in Switzerland INTERNATIONAL STANDARD ISO4262:1993(E) Petroleum products - Determination of carbon residue - Ramsbottom method Scope 1 of this International Standard. At the time of publi- cation, the editions indicated were valid. All standards This International Standard specifies a method for aresubjecttorevision,andpartiestoagreements determining the amount of carbon residue, in the based on this International Standard are encouraged range of 0,01 % (m/m) to 30,0 % (m/m), left after toinvestigatethepossibilityofapplyingthemostre evaporation and pyrolysis of an oil, and is intended to cent editions of the standards indicated below. provide some indication of relative coke-forming Members of IEC and ISO maintain registers of cur- tendency. The method is generally applicable to rela- rently valid International Standards. tively non-volatile petroleum products which partially decompose on distillationat atmospheric pressure ISO683-13:1986,Heat-treatable steels,alloy steels and free-cutting steels - Part 13: Wrought stainless NOTES steels. The term "carbon residue" is used throughout this In- ISO 3170:1988, Petroleum liquids Manual ternational Standard to designate the carbonaceous residue sampling. formed during evaporation and pyrolysis of a petroleum product. The residue is not entirely composed of carbon, but Iso 3171:1988, Petroleum liquids Automatic pipe- is a coke which can be further changed by pyrolysis. The line sampling. term "carbon residue" is retained in this method only in deference to its widespread use. Is03405:1988,PetroleumproductsDetermination The carbon residue of distillate and residual fuel oils of distllation characteristics. gives an approximate ranking of such fuels in terms of their propensitytoformdepositsinspecificapplications. 3 Principle 3 The presence of alkyl nitrates in distillate fuels, or ash- forming additives in either distillate or residual fuels, will 3.1 The test portion is weighed into a glass coking give carbon residue results that are higher than the corre sponding values of the fuel without additives. These values bulb having a capillary opening, and is placed in a may not correlate with the propensity of a fuel to form de- metal furnace maintained at a temperature of ap- posits. proximately 550 °C. The test portion is thus quic