1、Designation: D 1524 94 (Reapproved 2004)Standard Test Method forVisual Examination of Used Electrical Insulating Oils ofPetroleum Origin in the Field1This standard is issued under the fixed designation D 1524; the number immediately following the designation indicates the year oforiginal adoption or
2、, in the case of revision, the year of last 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 for visual examination is applicable tomineral oils of petrol
3、eum origin that have been used intransformers, oil circuit breakers, or other electrical apparatusas insulating or cooling media, or both.1.2 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
4、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 1500 Test Method for ASTM Color of Petroleum Prod-ucts (ASTM Color Scale)3. Summary of Test Method3.1 The color of the test specimen
5、 is estimated by visuallycomparing the color of a specified thickness of the sample witha series of artificial standard color disk filters in a specifiedcomparator.3.2 The condition of the test specimen is estimated byobservation of cloudiness, foreign particles, or suspendedmatter in the sample by
6、reflected light.4. Significance and Use4.1 By use of this test method the color and condition of atest specimen of oil may be estimated during a field inspection,thus assisting in the decision as to whether or not the sampleshould be sent to a central laboratory for full evaluation.Cloudiness, parti
7、cles of insulation, products of metal corrosion,or other undesirable suspended materials, as well as anyunusual change in color may be detected. For precise determi-nation of color in the laboratory, Test Method D 1500 shouldbe used.5. Apparatus5.1 Color Comparator3A color comparator suitable forest
8、imating the color of petroleum products on the ASTM ColorScale, and for the examination of the test specimen by reflectedlight (Tyndall beam effect).5.2 LightA light source such as a pen light with a No. 222bulb.5.3 ClothPhotographers focusing cloth.6. Preparation of Apparatus6.1 Open the front cove
9、r of the comparator housing, andplace the center of the color disk on the ring with the numberplates facing the operator. Close the cover. As the disk isrotated, the number plates representing ASTM Color Numberscan be read through the upper opening on the right-hand sideof the front cover. The align
10、ment is such that only one figure isvisible when a glass color standard is completely in the field ofview.6.2 The observation fields for colorimetric comparison canbe seen through the two central openings. Through the prismattachment, they are seen as half-fields. The right-hand field isproduced by
11、the test specimen in a tube which is placed in theopening at the right of the instrument, while the left-hand fieldis formed by one of the glass color standards.7. Procedure7.1 Color DeterminationsFill a tube with the test speci-men to a height convenient for full exposure in the observationfield an
12、d place it in the right-hand opening of the apparatus.Quickly make the color comparison by revolving the color disk1This test method is under the jurisdiction of ASTM Committee D27 onElectrical Insulating Liquids and Gases and is the direct responsibility of Subcom-mittee of D27.07 on Physical Tests
13、.Current edition approved Oct. 1, 2004. Published November 2004. Originallyapproved in 1968. Last previous edition approved in 1999 as D1524 94 (1999).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStan
14、dards volume information, refer to the standards Document Summary page onthe ASTM website.3The Hellige Oil Comparator, catalog No. 605-HT, with catalog No. 620C-55color disk, available from Orbco Hellige, 185 T Marine St., Farmingdale, NY11735,has been found to be suitable. This equipment may be mod
15、ified to accommodate aTyndall BeamAccessory.Aprism magnifier attachment, Catalog No. 600-PA, is alsoavailable if desired.AHellige Comparator, catalog No. 607-OC, has also been foundsuitable but is less convenient for field use.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West C
16、onshohocken, PA 19428-2959, United States.so that one standard after another is brought into the observa-tion field. When using the comparator with the prism attach-ment, view the color fields with the eye in line with the centerof the fields. The half-fields should be free of shadow effectwhich can
17、 be caused by off-center or oblique observation. Fornormal eyesight, the preferred viewing distance is approxi-mately 10 in. (25 cm). Caution: Do not place the eye close tothe comparator housing. Do not prolong the observation formore than 10 to 15 s. For very accurate readings, let the eyesrest bet
18、ween such intervals, preferably by viewing a gray orgreen surface. When a color match is obtained between the testspecimen and one of the glass standards, the figure seen in theupper opening in the front cover gives the direct reading. If thecolor of the test specimen is intermediate between those o
19、f twoglass standards, the result to be reported will be intermediatebetween their corresponding values and may be estimated byinterpolation. While taking readings, face the opal glass plate atthe back of the comparator directly toward the light. Take carethat pronounced shadows do not cause uneven i
20、llumination ofthe comparator fields. Northern exposure provides the bestdaylight for colorimetric determination, but any indirect lightfrom outdoors usually will be satisfactory. Avoid direct sun-light, even in the early morning or late afternoon.7.2 Tyndall Beam ExaminationProject a narrow focusedl
21、ight beam from the pen light upward through the test specimentube, using the photographic focusing cloth to exclude extra-neous light. Carefully examine the test specimen by means ofthis light. A test specimen of good oil will appear clean andsparkling. Haziness or cloudiness usually denotes moistur
22、e insuspension or sludge. If the dielectric strength is satisfactory,the cloudiness may be caused by oxidation products, in whichcase the neutralization number will probably be high and theinterfacial tension low. Particles of metals, insulation, carbon,and other matter will show up very markedly by
23、 reflected light.Report the oil as failing the test if the appearance of anycondition other than sparkling is observed. Open the compara-tor case and examine for sediment (sludge, metal particles,etc.)8. Report8.1 Report the following information:8.1.1 Color number,8.1.2 Description of any deviation
24、 from perfectly clear andsparkling, and any evidence of sediment,8.1.3 Approximate temperature of the oil at the time the testspecimen was taken, and8.1.4 Approximate temperature of the oil at time of obser-vation.9. Precision and Bias9.1 It is not practical to specify the precision and bias of this
25、test method because this is a rapid field examination to screentest specimens for further testing. If Test Method D 1500 isused in order to obtain precise determination of color in thelaboratory, the precision and bias are as specified in thatmethod.9.2 An interlaboratory investigation was conducted
26、 in 1968to support this test method. The results of this investigationwere first reported as RR 185: D97 D27 in January 1969.410. Keywords10.1 color; comparator; mineral oil; Tyndell beam effect;visual examinationASTM International takes no position respecting the validity of any patent rights asser
27、ted in connection 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
28、the responsible 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 receiv
29、e careful consideration 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 Intern
30、ational, 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).4For citation purposes, this report has now been designated as RR: D27-1008.D 1524 94 (2004)2
