1、Designation: D 2140 03Standard Test Method forCarbon-Type Composition of Insulating Oils of PetroleumOrigin1This standard is issued under the fixed designation D 2140; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method may be used to determine the carbon-type composition of mineral insulating oils by correlation withbasi
3、c physical properties. For routine analytical purposes iteliminates the necessity for complex fractional separation andpurification procedures. The test method is applicable to oilshaving average molecular weights from 200 to above 600, and0 to 50 aromatic carbon atoms.1.2 Carbon-type composition is
4、 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
5、relative density (specific grav-ity), and refractive index are the only experimental datarequired for use of this test method.1.3 This test method is useful for determining the carbon-type composition of electrical insulating oils of the typescommonly used in electric power transformers and transmis
6、-sion cables. It is primarily intended for use with new oils, eitherinhibited or uninhibited.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 prac
7、tices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:D 129 Test Method for Sulfur in Petroleum Products (Gen-eral Bomb Method)2D 445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids (and the Calculation of Dynamic
8、Viscosity)2D 923 Practices for Sampling Electrical Insulating Liquids3D 1218 Test Method for Refractive Index and RefractiveDispersion of Hydrocarbon Liquids2D 1481 Test Method for Density and Relative Density(Specific Gravity) of Viscous Materials by Lipkin Bicap-illary Pycnometer2D 2007 Test Metho
9、d for Characteristic Groups in RubberExtender and Processing Oils and Other Petroleum De-rived Oils by the Clay Gel Absorption ChromatographicMethod2D 2501 Test Method for Calculation of Viscosity-GravityConstant (VGC) of Petroleum Oils2D 3238 Test Method for Calculation of Carbon Distributionand St
10、ructural Group Analysis of Petroleum Oils by then-d-M Method4D 4052 Test Method for Density and Relative Density ofLiquids by Digital Density Meter43. 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
11、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 arecom
12、bined in paraffinic chain-type structures.NOTE 1The 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 hydro
13、carbon molecule, or maybe an alkyl group attached to an aromatic or naphthenic ring.4. Summary of Test Method4.1 A sample of the oil to be analyzed by this method is firsttested to determine its viscosity, density and relative density(specific gravity), and refractive index. From these measuredprope
14、rties the viscosity-gravity constant (VGC) and refractiv-ity intercept (ri) are obtained by calculation, using the equa-tions given. The calculated values of VGC and riare used with1This test method is under the jurisdiction of ASTM Committee D27 onElectrical Insulating Liquids and Gases and is the
15、direct responsibility of Subcom-mittee D27.07 on Physical Tests.Current edition approved March 10, 2003. Published May 2003. Originallyapproved in 1963 as D 2140 63 T. Last previous edition approved in 1997 asD 2140 97.2Annual Book of ASTM Standards, Vol 05.01.3Annual Book of ASTM Standards, Vol 10.
16、03.4Annual Book of ASTM Standards, Vol 05.02.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Fig. 1, to correlate those parameters with carbon-type compo-sition. The composition in terms of % CA,% CN, and % CPmay be read directly fro
17、m Fig. 1.NOTE 2Fig. 1 is a form of correlation chart that has been foundsatisfactory for use with this method. Other chart forms may be devisedand used in preference to Fig. 1 if it is determined that the data obtainedare consistent with similar data from Fig. 1. In addition, some users willfind it
18、convenient to develop a computer program or spreadsheet whichwill provide a consistent evaluation of the data.5. Significance and Use5.1 The primary purpose of this test method is to character-ize the carbon-type composition of an oil. It is also applicablein observing the effect on oil constitution
19、, of various refiningprocesses such as hydrotreating, solvent extraction, and soforth. It has secondary application in relating the chemicalnature of an oil to other phenomena that have been demon-strated to be related to oil composition.5.2 Results obtained by this method are similar to, but notide
20、ntical with, results obtained from Test Method D 3238. Therelationship between the two methods and the equations usedin deriving Fig. 1 are discussed in the literature.55.3 Although this test method tends to give consistentresults, it may not compare with direct measurement testmethods such as Test
21、Method D 2007.6. Apparatus6.1 No specific apparatus is required for use by this testmethod. However, to obtain the VGC and riparameters of Fig.1, certain measurements of basic physical properties of the test5Kurtz, S. S., King, R. W., Stout, W. J., Partikian, D. G., and Skrabek, E. A.,“Relationship
22、Between Carbon-Type Composition, Viscosity-Gravity Constant, andRefractivity Intercept of Viscous Fractions of Petroleum,” Analytical Chemistry,Vol28, pp 19281936 (1956).FIG. 1 Correlation Chart for Determining % CA,%CN, and % CPD 2140 032oil must be made. The apparatus required for those measure-me
23、nts is as specified in other ASTM test methods as detailed inSection 7.7. Procedure7.1 Obtain a uniform sample of the oil to be analyzed forcarbon-type composition, using sampling procedures as speci-fied in Practices D 923.7.2 Determine the viscosity, density and relative density(specific gravity),
24、 and refractive index of the sample experi-mentally by the procedures specified in the following testmethods:7.2.1 ViscositySee Test Method D 445.7.2.2 Density and Relative Density (Specific Gravity)SeeTest Method D 1481 or D 4052.7.2.3 Refractive Index See Test Method D 1218.8. Calculation8.1 From
25、the measured viscosity and specific gravity prop-erties of the oil sample (7.2) calculate the viscosity-gravityconstant, VGC, as follows (Note 3):VGC 5G 1 0.0887 2 0.776 log log 10V 2 4!1.082 2 0.72 log log 10V 2 4!where:G = relative density (specific gravity) at 15.6C (60F), andV = viscosity, cSt a
26、t 37.8C (100F).NOTE 3This equation for VGC was devised by Moore and Kaye.6Accurate VGC data may be obtained using other equations and othermeasurement temperatures. Test Method D 2501 gives some of thesealternatives.8.2 From the measured density and refractive index proper-ties of the oil sample (7.
27、2) calculate the refractivity intercept,ri, as follows:ri5 nD202 d/2!where:nD20= refractive index at 20C (68F) for D line ofsodium, andd = density at 20C (68F).8.3 Enter the correlation chart, Fig. 1, with the values ofVGC and ri, from 8.1 and 8.2. Read from Fig. 1 the corre-sponding values of % CA,
28、%CN, and % CP.8.4 For oils containing 0.8 % or more sulfur, the accuracy ofthis test method may be improved by applying a sulfurcorrection. This may be done by use of the following equations(Note 4):Sulfur correction for % CN52weight % S/0.288Sulfur correction for % CP51weight % S/0.216Sulfur correc
29、tion for % CA5 100 2 corrected % CN1 corrected % CP!NOTE 4Commercially available oils of the types to which this methodapplies normally have sulfur contents of less than 0.8 %. Therefore it isunlikely that a sulfur correction will be necessary. For new or experimen-tal oils, or whenever the true sul
30、fur content is unknown, the determinationof that quantity is recommended. A satisfactory method is described inTest Method D 129.69. Report9.1 Report the following information:9.1.1 Designation of test method used (D 2140),9.1.2 Sample identification.9.1.3 Percent of aromatic ring carbons (% CA).9.1
31、.4 Percent of naphthenic ring carbons (% CN), and9.1.5 Percent of paraffinic chain carbons (% CP).NOTE 5The total of 9.1.3, 9.1.4, and 9.1.5 should equal 100 %.10. Precision and Bias10.1 PrecisionThe precision of this test method has notbeen the subject of an interlaboratory test. This procedureinvo
32、lves calculations based on three experimentally observedvalues whose precisions are given in their respective methods.The precision of this test method (without the sulfur correc-tion), calculated from the precisions of these values and usingthe equations of Section 8, is as follows:10.1.1 Repeatabi
33、lity The difference between successiveresults obtained by the same operator with the same apparatusunder constant operating conditions on identical test materialshould, in the long run, in the normal and correct operation ofthe test method exceed the following values only in 1 case in20:CA=0% CA=25%
34、 CA=50%CA0.2 0.1 0.1CN0.3 0.2 0.5CP0.2 0.2 0.510.1.2 Reproducibility The difference between two singleand independent results obtained by different operators work-ing in different laboratories on identical test material should, inthe long run, exceed the following values only in 1 case in 20:CA=0% C
35、A=25% CA=50%CA0.2 0.2 0.2CN0.7 0.4 1.0CP0.5 0.4 1.1NOTE 6The precision of the carbon-type composition calculationvaries with position on the CACNCPplane of Fig. 1. Sensitivity toexperimental error for the CNand CPvalues is greatest at high CAvalues.The precision values given above do not apply if ro
36、utine test methods,rather than the precision methods specified, are used for determiningdensity and refractive index.10.2 BiasSince there is no accepted reference materialsuitable for determining the bias of this test method, nostatement on bias is being made. A comparison of results fromthis test m
37、ethod and a complex separation and purificationprocedure has been reported7for petroleum fractions, withagreement between the two methods being dependent on theviscosity-gravity constant of the fraction.6Proc., 15th API Annual Meeting, November 1934, Section II, p. 7.7Stout, W. J., et al, “Adsorptio
38、n and Physical Property Methods.” Symposium onComposition of Petroleum Oils, ASTM STP 224, ASTM, 1957, p. 230.D 2140 03311. Keywords11.1 carbon type; composition; electrical oils; mineral oils;oilsASTM International takes no position respecting the validity of any patent rights asserted in connectio
39、n with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible
40、technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consid
41、eration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Bar
42、r Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 2140 034
