ASTM_D_2140_-_08.pdf

Designation:D214008Standard Practice forCalculating Carbon-Type Composition of Insulating Oils ofPetroleum Origin1This standard is issued under the fixed designation D2140;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 practice may be used to determine the carbon-typecomposition of mineral insulating oils by correlation with basicphysical properties.For routine analytical purposes it elimi-nates the necessity for complex fractional separation andpurification procedures.The practice is applicable to oilshaving average molecular weights from 200 to above 600,and0 to 50 aromatic carbon atoms.1.2 Carbon-type composition is expressed as percentage ofaromatic carbons,percentage of naphthenic carbons,andpercentage of paraffinic carbons.These values can be obtainedfrom the correlation chart,Fig.1,if both the viscosity-gravityconstant(VGC)and refractivity intercept(ri)of the oil areknown.Viscosity,density and relative density(specificgravity),and refractive index are the only experimental datarequired for use of this test method.1.3 This practice is useful for determining the carbon-typecomposition of electrical insulating oils of the types commonlyused in electric power transformers and transmission cables.Itis primarily intended for use with new oils,either inhibited oruninhibited.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:2D129 Test Method for Sulfur in Petroleum Products(Gen-eral High Pressure Decomposition Device Method)D445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids(and Calculation of Dynamic Viscos-ity)D923 Practices for Sampling Electrical Insulating LiquidsD1218 Test Method for Refractive Index and RefractiveDispersion of Hydrocarbon LiquidsD1481 Test Method for Density and Relative Density(Spe-cific Gravity)of Viscous Materials by Lipkin BicapillaryPycnometerD2007 Test Method for Characteristic Groups in RubberExtender and Processing Oils and Other Petroleum-Derived Oils by the Clay-Gel Absorption Chromato-graphic MethodD2501 Test Method for Calculation of Viscosity-GravityConstant(VGC)of Petroleum OilsD3238 Test Method for Calculation of Carbon Distributionand Structural Group Analysis of Petroleum Oils by then-d-M MethodD4052 Test Method for Density,Relative Density,and APIGravity of Liquids by Digital Density Meter3.Terminology3.1 Definitions:3.1.1 percent of aromatic carbons(%CA)the weightpercent of the total carbon atoms present in an oil that arecombined in aromatic ring-type structures.3.1.2 percent of naphthenic carbons(%CN)the weightpercent of the total carbon atoms present in an oil that arecombined in naphthenic ring-type structures.3.1.3 percent of paraffnic carbons(%CP)the weightpercent of the total carbon atoms present in an oil that arecombined in paraffinic chain-type structures.1This practice is under the jurisdiction of ASTM Committee D27 on ElectricalInsulating Liquids and Gases and is the direct responsibility of SubcommitteeD27.07 on Physical Test.Current edition approved Nov.1,2008.Published December 2008.Originallyapproved in 1963 as D2140 63 T.Last previous edition approved in 2003 asD2140 03.DOI:10.1520/D2140-08.2For 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 NOTE1The resolution of carbon atoms into structural classificationsis independent of whether the structures exist as separate molecules or arecombined with other structural forms in a molecule.For example,aparaffinic chain may be either an aliphatic hydrocarbon molecule,or maybe an alkyl group attached to an aromatic or naphthenic ring.4.Summary of Practice4.1 A sample of the oil is tested to determine its viscosity,density and relative density(specific gravity),and refractiveindex.From these measured properties the viscosity-gravityconstant(VGC)and refractivity intercept(ri)are obtained bycalculation,using the equations given.The calculated values ofVGC and riare used with Fig.1,to correlate those parameterswith carbon-type composition.The composition in terms of%CA,%CN,and%CPmay be read directly from Fig.1.NOTE2Fig.1 is a form of correlation chart that has