1、Designation: D 2140 08Standard Practice forCalculating Carbon-Type Composition of Insulating Oils ofPetroleum Origin1This 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 ye
2、ar 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
3、 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
4、 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 a
5、nd relative density (specific grav-ity), 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 transmiss
6、ion 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, assoc
7、iated 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:2D 129 Test Method for Sulfur in Petroleum Products (Gen-er
8、al Bomb Method)D 445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids (and Calculation of Dynamic Viscos-ity)D 923 Practices for Sampling Electrical Insulating LiquidsD 1218 Test Method for Refractive Index and RefractiveDispersion of Hydrocarbon LiquidsD 1481 Test Method for Den
9、sity and Relative Density(Specific Gravity) of Viscous Materials by Lipkin Bicap-illary PycnometerD 2007 Test Method for Characteristic Groups in RubberExtender and Processing Oils and Other Petroleum-Derived Oils by the Clay-Gel Absorption Chromato-graphic MethodD 2501 Test Method for Calculation o
10、f Viscosity-GravityConstant (VGC) of Petroleum OilsD 3238 Test Method for Calculation of Carbon Distributionand Structural Group Analysis of Petroleum Oils by then-d-M MethodD 4052 Test Method for Density and Relative Density ofLiquids by Digital Density Meter3. Terminology3.1 Definitions:3.1.1 perc
11、ent 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.
12、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.NOTE 1The resolution of carbon atoms into structural classificationsis independent of whether the structures exist as separate molecules or arecom
13、bined 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.1This practice is under the jurisdiction of ASTM Committee D27 on ElectricalInsulating Liquids and Gases
14、 and is the direct responsibility of SubcommitteeD27.07 on Physical Test.Current edition approved Nov. 1, 2008. Published December 2008. Originallyapproved in 1963 as D 2140 63 T. Last previous edition approved in 2003 asD 2140 03.2For referenced ASTM standards, visit the ASTM website, www.astm.org,
15、 orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Summary of P
16、ractice4.1 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 calc
17、ulated 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.NOTE 2Fig. 1 is a form of correlation chart that has been foundsatisfactory for use with this method. Other chart f
18、orms 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 convenient to develop a computer program or spreadsheet whichwill provide a consistent evaluation of the data.5. Significanc
19、e and Use5.1 The primary purpose of this practice is to characterizethe carbon-type composition of an oil. It is also applicable inobserving the effect on oil constitution, of various refiningprocesses such as hydrotreating, solvent extraction, and soforth. It has secondary application in relating t
20、he chemicalFIG. 1 Correlation Chart for Determining % CA,%CN, and % CPD 2140 082nature of an oil to other phenomena that have been demon-strated to be related to oil composition.5.2 Results obtained by this practice are similar to, but notidentical with, results obtained from Test Method D 3238. The
21、relationship between the two and the equations used in derivingFig. 1 are discussed in the literature.35.3 Although this practice tends to give consistent results, itmay not compare with direct measurement test methods suchas Test Method D 2007.6. Apparatus6.1 No specific apparatus is required. Howe
22、ver, to obtain theVGC and riparameters of Fig. 1, certain measurements ofbasic physical properties of the test oil must be made. Theapparatus required for those measurements is as specified inASTM test methods as detailed in Section 7.7. Procedure7.1 Obtain a uniform sample of the oil to be analyzed
23、 forcarbon-type composition, using sampling procedures as speci-fied in Practices D 923.7.2 Determine the viscosity, density and relative density(specific gravity), and refractive index of the sample experi-mentally by the procedures specified in the following testmethods:7.2.1 ViscositySee Test Met
24、hod 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 the measured viscosity and specific gravity prop-erties of the oil sample (7.2) calculate the viscosity-gravityconstant, VGC, as follows
25、 (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 at 37.8C (100F).NOTE 3This equation for VGC was devised by Moore and Kaye.4Accurate VGC data may be obtained using other equations and ot
26、hermeasurement temperatures. Test Method D 2501 gives some of thesealternatives.8.2 From the measured density and refractive index proper-ties of the oil sample (7.2) calculate the refractivity intercept,ri, as follows:ri5 nD202 d/2!where:nD20= refractive index at 20C (68F) for D line ofsodium, andd
27、 = 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,%CN, and % CP.8.4 For oils containing 0.8 % or more sulfur, the accuracy ofthis practice may be improved by applying a sulfur correction
28、.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 correction for % CA5 100 2 corrected % CN1 corrected % CP!NOTE 4Commercially available oils of the types to which this methodapplies normally ha
29、ve 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 sulfur content is unknown, the determinationof that quantity is recommended. A satisfactory method is described inTest Method D 129.49. Repor
30、t9.1 Report the following information:9.1.1 Designation of practice used (D 2140),9.1.2 Sample identification.9.1.3 Percent of aromatic ring carbons (% CA).9.1.4 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
31、should equal 100 %.10. Keywords10.1 carbon type; composition; electrical oils; mineral oils;oilsASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determin
32、ation 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 technical committee and must be reviewed every five years andif not revised, either reapproved or wit
33、hdrawn. 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 consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that yo
34、ur comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.3Kurtz, S. S., King, R. W., Stout, W. J., Partikian, D. G., and Skrabek, E. A.,“Relationship Between Carbon-Type Composition, Viscosity-Gravity Constant, andRef
35、ractivity Intercept of Viscous Fractions of Petroleum,” Analytical Chemistry,Vol28, 1956, pp 19281936.4Proc., 15th API Annual Meeting, November 1934, Section II, p. 7.D 2140 083This standard is copyrighted by ASTM International, 100 Barr 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 084
