1、Designation: D1934 95 (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 ca
2、se 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 oxidati
3、ve 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 a
4、nd 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
5、 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 o
6、f 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) of
7、Electrical 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
8、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 circul
9、ating-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 stabili
10、ty 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-beakeroxid
11、ative 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
12、 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 specimen
13、s 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 Ga
14、ses and 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
15、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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United
16、States.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.NOTE 1Refer to Specification E145 for the measurement of thetemperature uniform
17、ity 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. If a fixed-shelf oven
18、is used, it is recom-mended that test specimen positions within the oven bechanged periodically (for example, at daily intervals) to mini-mize the effects of any temperature differentials that may exist.6.1.2 Procedure BWhen a metal catalyst, such as copper,is used, the rate of oxidation usually is
19、increased, and theprocedure becomes sensitive to movement of the oil past themetal surface. An aging oven equipped with a slowly rotatingshelf has been adopted for uniformity when a metal catalyst isused.3Other oven designs having satisfactory thermal qualityand a rotating shelf may be used.6.2 Beak
20、er, borosilicate glass, low-form, of 400-mL capac-ity. The approximate dimensions of a suitable beaker are100 mm in depth and 70 mm inside diameter. Clean the beakersused in the aging test, and thoroughly dry before use. Onerecommended cleaning procedure is as follows: Remove re-sidual oil from the
21、beaker by rinsing in mineral spirits orequivalent. Rinse thoroughly with an acid cleaning solutionconsisting of 3 parts nitric acid (HNO3) to 1 part sulfuric acid(H2SO4). Remove traces of cleaning solution by carefullyrinsing with distilled water followed by rinsing in acetone andair drying. (Ammoni
22、um persulfate is also a suitable cleaningreagent.)47. Reagents and Materials7.1 Purity of ReagentsUse reagent grade chemicals in alltests. Unless otherwise indicated, it is intended that all reagentsshall conform to the specifications of the Committee onAnalytical Reagents of the American Chemical S
23、ociety, wheresuch specifications are available.57.2 Hydrochloric Acid, 10 % volume solution from concen-trated hydrochloric acid.7.3 Nitric AcidConcentrated nitric acid (HNO3).7.4 Sulfuric AcidConcentrated sulfuric acid (H2SO4).7.5 Metal Catalyst with 15 cm2of clean surface availablefor exposure to
24、the oil for use in Procedure B. If the metalcatalyst is copper wire, it is convenient to wind an appropriatelength into a loose hank which is then cleaned to remove oil,oxide, and the other extraneous matter. The metal catalyst mayalso be used in the form of strips, but the strips require specialatt
25、ention to maintain the desired amount of exposed surface.One good method of cleaning copper hanks is to immerse thehank for 30 s in a 10 % solution of hydrochloric acid (HCl),after which the hank is rinsed three times in distilled water thenin acetone and air dried. The cleaned hank should be handle
26、dwith clean tongs.8. Procedure AAging Without a Metal Catalyst8.1 Obtain the oil sample in accordance with PracticesD923.8.2 Adjust the oven temperature to 115 6 1C.8.3 Pour without preheating 300 mL of the test specimen tobe tested into a clean dry 400-mL beaker. Oil depth in thebeaker will be appr
27、oximately 75 mm. Measure the mass of theoil before test.8.4 Place the beaker containing the test specimen in thepreheated oven. To minimize temperature fluctuation it isdesirable to place all test specimens in the oven at the sametime.8.5 Start the oven shelf into rotation if the oven is soequipped.
28、8.6 Remove the test specimen from the oven at the end ofthe 96-h aging period and measure the mass of the oil.8.7 Determine the condition of the aged test specimen bymeans of appropriate test methods. The condition of an unagedtest specimen usually should also be determined at the sametime for compa
29、rison.9. Procedure BAging with a Metal Catalyst9.1 Proceed exactly as in Procedure A (Section 8) exceptbefore placing the beaker in the oven add the metal catalyst tothe oil specimen in the beaker, with the specified amount ofsurface exposed to the oil.9.2 Measure the mass of the oil plus catalyst b
30、efore andafter the test.10. Report10.1 Report the following information:10.1.1 Designation of this test method (D1934),10.1.2 Whether or not a metal catalyst was used (ProcedureA or B) and the nature and form of the metal catalyst, if used,10.1.3 Test specimen identification,10.1.4 Values of the pro
31、perty or properties measured on theaged (and unaged) test specimens, and10.1.5 Designations of the test methods used to determinethe condition of the oil test specimens.10.1.6 The measured change in mass percent of the oil tovalidate the test (less than 10 % evaporation).11. Precision and Bias611.1
32、PrecisionThe precision of the open-beaker oxidativeaging defined by this test method has not yet been adequately3Asuitable type oven is described in “Life Test for Transformer Oils,”Appendixto Report of Committee D09 on Electrical and Electronic Insulating Materials,Proceedings, ASTM, Vol 27, Part I
33、, 1927 pp. 541549.4The sole source of supply of ammonium persulfate (available as Nochromix)known to the committee at this time is Interex Corp., 3 Strathmore Rd., Natick, MA01760. If you are aware of alternative suppliers, please provide this information toASTM International Headquarters. Your comm
34、ents will receive careful consider-ation at a meeting of the responsible technical committee,1which you may attend.5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Soc
35、iety, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.6Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting R
36、esearch Report RR:D27-1007.D1934 95 (2012)2defined in accordance with Practice E177. However, precisionestimates for both single-laboratory repeatability and multi-laboratory reproducibility of changes in oil dissipation factor(power factor) due to open-beaker oxidative aging are availablefrom a 195
37、859 round robin with ten participating laboratories.11.2 In the case of four naphthenic insulating oils withdifferent viscosities (55, 100, 760, and 2200 SUS at 100F, and38, 39, 60, and 105 SUS, respectively, at 210F) with andwithout 2.8 cm2of copper wire catalyst, random errors wereproportional to
38、the ratio, Q:Q 5dissipation factor after agingdissipation factor before aging11.2.1 The data were normalized by a logarithmic transfor-mation.11.3 RepeatabilityThe standard deviation of the quantitylogQ has been estimated to be 0.07 (coefficient of variation ofQ = 18 %) for duplicate aging tests run
39、 at the same time in agiven oven in the same laboratory. The standard deviation oflogQ has been estimated to be 0 (coefficient of variation of Q= 60 %) for duplicate aging tests run at different times in thesame laboratory.11.4 ReproducibilityThe standard deviation of the quan-tity logQ has been fou
40、nd to be 0.37 (coefficient of variation ofQ = 135 %) for duplicate aging tests run in different labora-tories.11.5 BiasSince there is no accepted reference materialsuitable for determining the bias for the procedure in this testmethod for measuring the true value of the property involved,no statemen
41、t on bias is being made.12. Keywords12.1 aging; electrical insulating oil; open beaker test; oxi-dative; petroleumASTM 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 adv
42、ised 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 technical committee and must be reviewed every five years andif not revised, either
43、 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 consideration at a meeting of theresponsible technical committee, which you may attend. I
44、f 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 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Indivi
45、dual 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D1934 95 (2012)3
