ASTM_D_7590_-_09_2014.pdf

Designation:D759009(Reapproved 2014)Standard Guide forMeasurement of Remaining Primary Antioxidant Content InIn-Service Industrial Lubricating Oils by Linear SweepVoltammetry1This standard is issued under the fixed designation D7590;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.INTRODUCTIONUnder normal thermal and oxidative working conditions,which degrade the chemical compositionof the oils basestock and gradually deplete the oils additive package,good oil condition monitoringprocedures are necessary to determine and planning corrective actions before the oil propertieschanges have passed their warning limits.Antioxidant monitoring practices are a vital part of modernoil condition monitoring practices to achieve lubrication excellence.This guide addresses the correctguidelines for voltammetric data interpretation.1.Scope1.1 This guide covers the voltammetric analysis for quali-tative measurements of primary antioxidants in new or in-service type industrial lubricants detectable in concentrationsas low as 0.0075 mass percent up to concentrations found innew oils by measuring the amount of current flow at a specifiedvoltage in the produced voltammogram.1.2 This guide can be used as a resource for a conditionmonitoring program to track the oxidative health of a range ofindustrial lubricants which contain primary antioxidants.Inorder to avoid excessive degradation of the base-oil,theseprimary antioxidants play a major role to protect the lubricantsagainst thermal-oxidative degradation.This guide can helpusers with interpretation and troubleshooting results obtainedusing linear sweep voltammetry(LSV).1.3 When used as part of oil condition monitoring practices,it is important to apply trend analysis to monitor the antioxi-dant depletion rate relative to a baseline sample rather than usevoltammetry for an absolute measurement of the antioxidantconcentration.The trending pattern provides a proactive meansto identify the level of oil degradation or abnormal changes inthe condition of the in-service lubricant.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 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:2D1193 Specification for Reagent WaterD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4378 Practice for In-Service Monitoring of Mineral Tur-bine Oils for Steam,Gas,and Combined Cycle TurbinesD6224 Practice for In-Service Monitoring of Lubricating Oilfor Auxiliary Power Plant EquipmentD6304 Test Method for Determination of Water in Petro-leum Products,Lubricating Oils,and Additives by Cou-lometric Karl Fischer TitrationD6810 Test Method for Measurement of Hindered PhenolicAntioxidant Content in Non-Zinc Turbine Oils by LinearSweep VoltammetryD6971 Test Method for Measurement of Hindered Phenolicand Aromatic Amine Antioxidant Content in Non-zincTurbine Oils by Linear Sweep VoltammetryD7214 Test Method for Determination of the Oxidation ofUsed Lubricants by FT-IR Using Peak Area IncreaseCalculation1This guide is under the jurisdiction of ASTM Committee D02 on PetroleumProducts,Liquid Fuels,and Lubricants and is the direct responsibility of Subcom-mittee D02.09.0C on Oxidation of Turbine Oils.Current edition approved May 1,2014.Published July 2014.Originally approvedin 2009.Last previous edition approved in 2009 as D7590 091.DOI:10.1520/D7590-09R14.2For 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 2.2 ISO Standards:3ISO 4406.2 Hydraulic fluid powerFluidsMethod forcoding the level of contamination by solid particles2.3 Other Standards:4VGB Guideline VGB-M 416 M In-Service Monitoring ofTurbine Oils3.Oil Condition Monitoring Programs3.1 Most industrial lubricants consist of mineral or syntheticoils compounded with oxidation and rust inhibitors.Dependingupon their application and the performance level desired,specific required amounts of other additives such as metaldeactivators,pour depressants,extreme pressure additives,andfoam suppressants can also be present.3.2 With modern formulations of industrial lubricants,theantioxidants play a major role in protecting the base-oil againstexcessive degradation.To prevent this base-oil