ASTM_D_1934_-_95_2012.pdf

Designation:D193495(Reapproved 2012)Standard Test Method forOxidative Aging of Electrical Insulating Petroleum Oils byOpen-Beaker Method1This standard is issued under the fixed designation D1934;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers two procedures for subjectingelectrical insulating oils to oxidative aging:1.1.1 Procedure A,without a metal catalyst,and1.1.2 Procedure B,with a metal catalyst.1.2 This test method is applicable to oils used as impreg-nating or pressure media in electrical power transmissioncables if less than 10%of the oil evaporates during the agingprocedures.It applies and is generally useful primarily in theevaluation and quality control of unused oils,either inhibitedor uninhibited.1.3 The values stated in SI units are to be regarded asstandard.The values given in parentheses are for informationonly.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D664 Test Method for Acid Number of Petroleum Productsby Potentiometric TitrationD923 Practices for Sampling Electrical Insulating LiquidsD924 Test Method for Dissipation Factor(or Power Factor)and Relative Permittivity(Dielectric Constant)of Electri-cal Insulating LiquidsD1169 Test Method for Specific Resistance(Resistivity)ofElectrical Insulating LiquidsE145 Specification for Gravity-Convection and Forced-Ventilation OvensE177 Practice for Use of the Terms Precision and Bias inASTM Test Methods3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 metal catalystany metal(for example,copper)thateither increases the rate of oxidation of the oil or reacts with theoxidation products to increase oil dielectric loss.3.1.2 oxidative agingexposure of oil to oxygen undercertain specified conditions.4.Summary of Test Method4.1 A 300 mL volume of oil,contained in 400 mL beaker isaged for 96 h in a circulating-air oven controlled at 115C,either with or without the presence of catalyst.5.Significance and Use5.1 Open-beaker oxidative aging methods have been usedfor many years in laboratories of oil companies,electricalequipment manufacturers,and electric utility companies inter-ested in the stability of electrical insulating oils under oxidativeconditions.They are particularly useful as a check on thecontinuity of production and shipment of insulating oils.Theyare also useful as process and product checks for applicabletype oils.5.2 Specification limits for oils subjected to open-beakeroxidative aging by this method are established by agreementbetween individual producers and consumers of applicabletype oils.These properties of the oil involved in specificationlimits for aging stability may be measured after the oxidativeaging(and sometimes before aging)by appropriate test meth-ods such as Test Method D924,Test Method D1169,and TestMethod D664.6.Apparatus6.1 Oven,electrically heated,thermostatically controlled,capable of maintaining a constant temperature of 115 6 1C(239 6 2F).Use an oven with a testing chamber large enoughto test the anticipated number of test specimens at one time.Auniformity of temperature within 61%of the differentialbetween oven and ambient temperatures is required.(See Note1.)Circulate air in the chamber with a low velocity fan during1This test method is under the jurisdiction of ASTM Committee D27 onElectrical Insulating Liquids and Gasesand is the direct responsibility of Subcom-mittee D27.06 on Chemical Test.Current edition approved Feb.1,2012.Published February 2012.Originallyapproved in 1962.Last previous edition approved in 2005 as D1934 95(2005).DOI:10.1520/D1934-95R12.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 the aging period.The volume and condition of the circulatedair is not considered to be critical.It is recommended that theoven provide several air changes per hour,and that vapors andfumes be removed if present.NOTE1Refer to Specification E145 for the measurement of thetemperature uniformity of the oven.6.1.1 Procedure AFor test specimens aged in the absenceof a metal catalyst the choice of a suitable oven design is notcritical.Either fixed-or rotating-shelf stage ovens of satisfac-tory thermal quality may be used,although a rotating-shelfoven is preferred.I