1、Designation: D 2129 05Standard Test Method forColor of Clear ElectricalInsulating Liquids (Platinum-Cobalt Scale)1This standard is issued under the fixed designation D 2129; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、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 standard describes a test method for the visualdetermination of the color of clear insulating liquids.1.2 The
3、 values stated in acceptable metric units are to beregarded as the standard.1.3 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 determi
4、ne the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagent WaterD 1209 Test Method for Color of Clear Liquids (Platinum-Cobalt Scale)D 1500 Test Method for ASTM Color of Petroleum Prod-ucts (ASTM Color Scale)3. Summary of
5、Test Method3.1 The color determined by this test method is derived bycomparing the color of the test specimen with that of a seriesof numbered color reference standards using transmitted lightunder prescribed conditions. The procedure described is basedon that for measuring the color of water and cl
6、ear liquidsaccording to the platinum-cobalt scale. This scale is suitablefor measurements over the color range from 5 to 300. The colorof test specimens darker than 300 on the platinum-cobalt scalemust be measured according to the ASTM Color Scale asdescribed in Test Method D 1500. The use of the pl
7、atinum-cobalt scale in this way is primarily of value as an expansionof the lower part of the ASTM Color Scale, especially in therange between 0 and 1.4. Significance and Use4.1 Color is significant chiefly as an indicator of contami-nation in electrical insulating liquids. Frequently this contami-n
8、ation is the result of solvent action in the apparatus involvedor it may indicate possible contamination. No definite relation-ship can be established between color and the physical andelectrical characteristics of the liquid; for that reason color initself has limited value as a measure of conditio
9、n. For moreprecise determination of color, Test Method D 1209 may beused.5. Apparatus5.1 Color Comparison TubesMatched, tall-form Nesslertubes, graduated at the 50-mL mark, and provided withground-on, optically clear glass caps.5.2 Color ComparatorA color comparator constructed topermit visual compa
10、rison of light transmitted through tall-formNessler tubes in the direction of their longitudinal axes. Thecomparator should be constructed so that white light is passedthrough or reflected off a white glass plate and directed withequal intensity through the tubes, and should be shielded sothat no li
11、ght enters the tubes from the side.36. Reagents6.1 Purity of ReagentsUse reagent grade chemicals in alltests. Unless otherwise indicated, all reagents will conform tothe specifications of the Committee on Analytical Reagents ofthe American Chemical Society, where such specifications areavailable.4Ot
12、her grades may be used, provided it is firstascertained that the reagent is of sufficiently high purity topermit its use without lessening the accuracy of the determi-nation.6.2 Purity of WaterUse reagent water conforming toSpecification D 1193.6.3 Solvent, suitable, clear.6.4 Cobaltous Chloride (Co
13、Cl26H2O).1This test method is under the jurisdiction of ASTM Committee on D27 onElectrical Insulating Liquids and Gases and is the direct responsibility of Subcom-mittee D 27.07 on Physical Tests.Current edition approved Dec. 1, 2005. Published December 2005. Originallyapproved in 1962 as D 2129 - 6
14、2 T. Last previous edition approved in 1997 asD 2129 - 97.2For 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.3A
15、unit available from Scientific Glass and Instruments, Inc. P.O. Box 6,Houston, TX 77001, has been found suitable for this purpose.4“Reagent Chemicals, American Chemical Society Specifications,” Am. Chemi-cal Soc., Washington, DC. For suggestions on the testing of reagents not listed bytheAmerican Ch
16、emical Society, see “Reagent Chemicals and Standards,” by JosephRosin, D. Van Nostrand Co., Inc., New York, NY and the “United StatesPharmacopeia.”1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.5 Hydrochloric Acid (sp gr 1.19)Conc
17、entrated hydro-chloric acid (HCl).6.6 Potassium Chloroplatinate (K2PtCl6).7. Preparation of Color Standards7.1 Platinum-Cobalt Stock SolutionDissolve 1.245 g ofK2PtCl6(containing 0.5 g of platinum) and 1.000 g ofCoCl26H2O (containing about 0.25 g of cobalt) in water. Add100 mL of HCl (sp gr 1.19) an
18、d dilute to 1 L with water. Thissolution has a color of 500.NOTE 1The color standard stock solution (platinum-cobalt solution)can be purchased with a color of 500 from laboratory supply firms.7.2 Platinum-Cobalt Standards5The unit of color is thatcolor produced by 1 mg of platinum per litre. From th
19、e stocksolution, prepare color standards, as given in Table 1,bydiluting the required volumes to 50 mL with water in theNessler tubes. Cap the tubes and seal the caps with shellac ora waterproof cement.8. Procedure8.1 Introduce 50 mL of the test specimen into a Nesslertube, passing the sample throug
20、h a filter if it has any visible testspecimen turbidity. Cap the tube, place in the comparator, andcompare with the standards.8.2 If the recorded color of the test specimen is greater than300, do not use the platinum-cobalt scale. Use Test MethodD 1500 to measure color.9. Report9.1 Report which meth
21、od was used, Test Method D 2129 orTest Method D 1500.9.2 Report as the color, the number of the standard that mostnearly matches the test specimen. In the event that the colorlies midway between two standards, report the darker of thetwo.9.3 If, owing to differences in hue between the test specimena
22、nd the standards, a definite match cannot be obtained, reportthe range over which an apparent match is obtained, and reportthe test specimen as “off-hue.”10. Precision and Bias10.1 An estimate of the repeatability has been developedbased on data supplied by a single laboratory. These data arepresent
23、ed in Appendix X1. These results suggest that anestimate of the 95 % repeatability limit for color by TestMethod D 2129 is 15.1 % of the test result or approximately4.5 when the mean color level is 30.10.2 It is not possible to specify the reproducibility of theprocedure in Test Method D 2129 for me
24、asuring color of cleardielectric liquids because there is an insufficient number oflaboratories available to participate in an interlaboratory roundrobin program required to produce the necessary data.10.3 No information can be presented on the bias of theprocedure in Test Method D 2129 for measurin
25、g the color ofclear dielectric liquids because no material having an acceptedreference value is available.11. Keywords11.1 clear liquids; color; insulating liquids; platinum-cobaltcolor scaleAPPENDIXX1. REPEATABILITY DATA ESTIMATE FOR A SINGLE OPERATOR TEST SERIES OF ANALYSESX1.1 Data are given from
26、 a single laboratory, singleoperator analysis for the visual determination of the color ofclear electrical insulating liquids. The test results are from asingle set of test results on a single sample and are presented inTable X1.1. The standard deviations and repeatability arecalculated from a sampl
27、e with a nominal color number of 30and represent variations from that particular color number.5The preparation of these platinum-cobalt standards was originally described byHazen, A., American Chemical Journal, ACJOA, Vol 14, 1982, p. 300. Thedescription given in this Test Method D 2129 is identical
28、 with that given in theStandard Methods for the Examination of Water and Sewage, American PublicHealth Assn., Ninth Edition, p. 14. A description is also given by Scott, W. W.,Standard Method of Chemical Analysis, D. Van Nostrand Co., Inc., Fifth Edition,Vol 2, p. 2048.TABLE 1 Platinum-Cobalt Color
29、Standards (for 50-mL Tubes)ColorStandardNumberStockSolution,mLColorStandardNumberStockSolution,mLColorStandardNumberStockSolution,mL5 0.5 35 3.5 150 15.010 1.0 40 4.0 200 20.015 1.5 50 5.0 250 25.020 2.0 60 6.0 300 30.025 2.5 70 7.0 350 35.030 3.0 100 10.0 400 40.0450 45.0D 2129 052ASTM Internationa
30、l 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 determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their o
31、wn 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 withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be a
32、ddressed 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 your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards,
33、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. 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).TABLE X1.1 Results of Separate Color DeterminationSample Report13023325435363073839310 30Average 29.5Sr1.58CV, % 5.4r, % 15.1D 2129 053
