1、Designation:D212905(Reapproved 2010)Standard Test Method forColor of Clear ElectricalInsulating Liquids(Platinum-Cobalt Scale)1This standard is issued under the fixed designation D2129;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,
2、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 standard describes a test method for the visualdetermination of the color of clear insulating liquids.1.2
3、The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3This 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
4、safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD1209 Test Method for Color of Clear Liquids(Platinum-Cobalt Scale)D1500 Test Method for ASTM Color of Petroleum Products
5、(ASTM Color Scale)3.Summary of 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 measu
6、ring the color of water and clear 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 Meth
7、od D1500.The use of the platinum-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.Fr
8、equently this contami-nation 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
9、a measure of condition.For moreprecise determination of color,Test Method D1209 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
10、 visual comparison 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 s
11、othat no light 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 areavaila
12、ble.4Other 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.1This test method is under the jurisdiction of ASTM Committee on D27 onElectrical Insulating Liquids and Gases and is th
13、e direct responsibility of Subcom-mittee D27.07 on Physical Test.Current edition approved Nov.1,2010.Published November 2010.Originallyapproved in 1962 as D2129-62 T.Last previous edition approved in 2005 asD2129-05.DOI:10.1520/D2129-05R10.2For referenced ASTM standards,visit the ASTM website,www.as
14、tm.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 unit available from Scientific Glass and Instruments,Inc.P.O.Box 6,Houston,TX 77001,has been found suitable for this purpos
15、e.4“Reagent Chemicals,American Chemical Society Specifications,”Am.Chemi-cal Soc.,Washington,DC.For suggestions on the testing of reagents not listed bytheAmerican Chemical Society,see“Reagent Chemicals and Standards,”by JosephRosin,D.Van Nostrand Co.,Inc.,New York,NY and the“United StatesPharmacope
16、ia.”Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.2 Purity of WaterUse reagent water conforming toSpecification D1193.6.3 Solvent,suitable,clear.6.4 Cobaltous Chloride(CoCl26H2O).6.5 Hydrochloric Acid(sp gr 1.19)Concentrated 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(