1、Designation: D 1209 05Standard Test Method forColor of Clear Liquids (Platinum-Cobalt Scale)1This standard is issued under the fixed designation D 1209; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A n
2、umber in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This test method describes a procedure for the visual
3、measurement of the color of essentially light colored liquids(Note 1). It is applicable only to materials in which thecolor-producing bodies present have light absorption charac-teristics nearly identical with those of the platinum-cobalt colorstandards used.NOTE 1A procedure for estimating color of
4、 darker liquids, describedfor soluble nitrocellulose base solutions, is given in Guide D 365.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 For purposes of determining conformance of an ob-served or a calculated value u
5、sing this test method to relevantspecifications, test result(s) shall be rounded off “to the nearestunit” in the last right-hand digit used in expressing thespecification limit, in accordance with the rounding-off methodof Practice E29.1.4 This standard does not purport to address all of thesafety c
6、oncerns, 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. For specific hazardstatements see Section 6.1.5 For specific hazard informatio
7、n, see the Material SafetyData Sheet.2. Referenced Documents2.1 ASTM Standards:2D 156 Test Method for Saybolt Color of Petroleum Prod-ucts (Saybolt Chromometer Method)D 365 Guide for Soluble Nitrocellulose Base SolutionsD 1193 Specification for Reagent WaterE29 Practice for Using Significant Digits
8、in Test Data toDetermine Conformance with SpecificationsE 202 Test Methods for Analysis of Ethylene Glycols andPropylene GlycolsE 346 Test Methods for Analysis of Methanol3. Significance and Use3.1 The property of color of a solvent varies in importancewith the application for which it is intended,
9、the amount ofcolor that can be tolerated being dependent on the colorcharacteristics of the material in which it is used. The paint,varnish, and lacquer solvents, or diluents commercially avail-able on todays market normally have little or no color. Thepresence or absence of color in such material i
10、s an indicationof the degree of refinement to which the solvent has beensubjected or of the cleanliness of the shipping or storagecontainer in which it is handled, or both.3.2 For a number of years the term “water-white” wasconsidered sufficient as a measurement of solvent color.Several expressions
11、for defining “water-white” gradually ap-peared and it became evident that a more precise color standardwas needed. This was accomplished in 1952 with the adoptionof Test Method D 1209 using the platinum-cobalt scale. Thistest method is similar to the description given in StandardMethods for the Exam
12、ination of Water and Waste Water3and isreferred to by many as “APHAColor.” The preparation of theseplatinum-cobalt color standards was originally described by A.Hazen in the American Chemical Journal4in which heassigned the number 5 (parts per ten thousand) to his platinum-cobalt stock solution. Sub
13、sequently, in their first edition (1905)of Standard Methods for the Examination of Water, theAmerican Public Health Association, using exactly the sameconcentration of reagents, assigned the color designation 500(parts per million) which is the same ratio. The parts permillion nomenclature is not us
14、ed since color is not referreddirectly to a weight relationship. It is therefore recommendedthat the incorrect term “Hazen Color” should not be used.Also,because it refers primarily to water, the term “APHA Color” is1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Relate
15、d Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.35 on Solvents, Plasticizers, and Chemical Intermediates.Current edition approved May 15, 2005. Published May 2005. Originallyapproved in 1952. Last previous edition approved in 2000 as D 1209 00.2For referen
16、ced 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.3Standard Methods for the Examination of Water and Waste Water, M. Franso
17、n,Ed., American Public Health Assoc., 14th ed., 1975, p. 65.4Hazen, A., “New Color Standard for Natural Waters,” American ChemicalJournal, Vol XIV, 1892, p. 300310.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, Wes
18、t Conshohocken, PA 19428-2959, United States.undesirable. The recommended nomenclature for referring tothe color of organic liquids is “Platinum-Cobalt Color, TestMethod D 1209.”3.3 The petroleum industry uses the Saybolt colorimeterTest Method D 156 for measuring and defining the color ofhydrocarbo
19、n solvents; however, this system of color measure-ment is not commonly employed outside of the petroleumindustry. It has been reported by various sources that a Sayboltcolor of +25 is equivalent to 25 in the platinum-cobalt systemor to colors produced by masses of potassium dichromateranging between
20、 4.8 and 5.6 mg dissolved in 1 L of distilledwater. Because of the differences in the spectral characteristicsof the several color systems being compared and the subjectivemanner in which the measurements are made, exact equivalen-cies are difficult to obtain.4. Apparatus4.1 Spectrophotometer, equip
21、ped for liquid samples and formeasurements in the visible region.NOTE 2The spectrophotometer used must be clean and in first-classoperating condition. The instrument should be calibrated in accordancewith the instructions given in the Standards for Checking the Calibrationof Spectrophotometers (200
22、to 1000 nm).54.2 Spectrophotometer Cells, matched having a 10-mm lightpath.4.3 Color Comparison TubesMatched 100-mL, tall-formNessler tubes, provided with ground-on, optically clear, glasscaps. Tubes should be selected so that the height of the 100-mLgraduation mark is 275 to 295 mm above the bottom
23、 of thetube.4.4 Color ComparatorA color comparator constructed topermit visual comparison of light transmitted through tall-form, 100-mL Nessler tubes in the direction of their longitu-dinal axes. The comparator should be constructed so that whitelight is passed through or reflected off a white glas
24、s plate anddirected with equal intensity through the tubes, and should beshielded so that no light enters the tubes from the side.65. Reagents5.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the spec
25、ifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.7Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.
26、5.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water conformingto Type IV of Specification D 1193.5.3 Cobalt Chloride (CoCl26H2O).5.4 Hydrochloric Acid (sp gr 1.19)Concentrated hydro-chloric acid (HCl).5.5 Potassium Chloroplatinate (K2PtCl6).6.
27、Platinum-Cobalt Reference Standards6.1 Platinum-Cobalt Stock Solution Dissolve 1.245 g ofpotassium chloroplatinate (K2PtCl6) and 1.00 g of cobaltchloride (CoCl26H2O) in water. Carefully add 100 mL ofhydrochloric acid (HCl, sp gr 1.19) and dilute to 1 L withwater. The absorbance of the 500 platinum-c
28、obalt stock solu-tion in a cell having a 10-mm light path, with reagent water ina matched cell as the reference solution,8must fall within thelimits given in Table 1.NOTE 3This stock solution is commercially available from reputablechemical suppliers.6.2 Platinum-Cobalt StandardsFrom the stock solut
29、ion,prepare color standards in accordance with Table 2 by dilutingthe required volumes to 100 mL with water in the Nessler5See NIST Letter Circular LC-1017.6The sole source of supply of the unit known to the committee at this time isScientific Glass and Instruments, Inc., P.O. Box 6, Houston, TX 770
30、01. If you areaware of alternative suppliers, please provide this information to ASTM Interna-tional Headquarters. Your comments will receive careful consideration at a meetingof the responsible technical committee,1which you may attend.7Reagent Chemicals, American Chemical Society Specifications, A
31、mericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (
32、USPC), Rockville,MD.8See the manufacturers instruction manual for complete details for operatingthe spectrophotometer.TABLE 1 Absorbance Tolerance Limits For No. 500 Platinum-Cobalt Stock SolutionWavelength, nm Absorbance430 0.110 to 0.120455 0.130 to 0.145480 0.105 to 0.120510 0.055 to 0.065TABLE 2
33、 Platinum-Cobalt Color StandardsColor StandardNumberStock Solution,mLColor StandardNumberStock Solution,mL5 1 70 1410 2 100 2015 3 150 3020 4 200 4025 5 250 5030 6 300 6035 7 350 7040 8 400 8050 10 450 9060 12 500 100AAThis is platinum-cobalt color No. 10 in Guide D 365.TABLE 3 Platinum-Cobalt Color
34、 Standards for Very Light ColorsColor StandardNumberStock Solution,mLColor StandardNumberStock Solution,mL1 0.20 9 1.802 0.40 10 2.003 0.60 11 2.204 0.80 12 2.405 1.00 13 2.606 1.20 14 2.807 1.40 15 3.008 1.60D1209052tubes. Cap the tubes and seal the caps with shellac or awaterproof cement. When pro
35、perly sealed and stored, thesestandards are stable for at least 1 year and do not degrademarkedly for 2 years.96.2.1 For a more precise measurement of light colors below15 platinum-cobalt, prepare color standards from the stocksolution in accordance with Table 3 by diluting the requiredvolumes to 10
36、0 mL with water in the Nessler tubes. Use asemi-microburet for measuring the required amount of stocksolution.7. Procedure7.1 Introduce 100 mL of specimen into a Nessler tube,passing the specimen through a filter if it has any visibleturbidity. Cap the tube, place in the comparator, and comparewith
37、the standards.8. Report8.1 Report as the color the number of the standard that mostnearly matches the specimen. In the event that the color liesmidway between two standards, report the darker of the two.8.2 If, owing to differences in hue between the specimenand the standards, a definite match canno
38、t be obtained, reportthe range over which an apparent match is obtained, and reportthe material as “off-hue.”9. Precision9.1 Color Samples with Pt-Co Color Greater than 2510:9.1.1 These precision statements are based upon an inter-laboratory study in which six platinum-cobalt standards havingvalues
39、of 25, 75, 170, 265, 385, and 475 were prepared inaccordance with the instructions given in Section 6 of this testmethod and were given coded labels. These solutions weretested by one analyst in each of ten different laboratoriesmaking a single observation on one day and then repeating theobservatio
40、n on a second day. The analysts were requested toestimate the color to the nearest one unit for solutions below 40platinum-cobalt, to the nearest five units for solutions between40 and 100 platinum-cobalt and to the nearest ten units forsolutions above 100 platinum-cobalt. Based on the results ofthi
41、s interlaboratory study, the following criteria, calculatedaccording to RR-D02-1007, should be used for judging theacceptability of results at the 95 % confidence level when theresults are obtained under optimum conditions where the hueof the sample matches exactly the hue of the standards. Poorprec
42、ision will be obtained in varying degrees as the hue of thesample departs from that of the standards.9.1.1.1 RepeatabilityTwo results, obtained by the sameanalyst should be considered suspect if they differ by morethan:r = 0.027 (X + 92) platinum-cobalt unitswhere X is the average of the two results
43、.9.1.1.2 ReproducibilityTwo results, obtained by analystsin different laboratories, should be considered suspect if theydiffer by more than: R = 0.087 ( X + 92) platinum-cobalt unitswhere X is the average of the two results.9.1.1.3 Table 4 shows precision values for samples withPt-Co Color of greate
44、r than 25.9.2 Color Samples with Pt-Co Color Less than 2511:9.2.1 The results of two interlaboratory studies were pooledto give precision values calculated according to RR-D02-1007.One study of glycols included 4 samples and 7 laboratories; theother study included 5 samples and 6 laboratories. Based
45、 on thepooled repeatability and reproducibility standard deviations,the following criteria should be used for judging, at the 95 %confidence level, the acceptability of results obtained onsamples with less than 25 Pt-Co Color.9.2.1.1 ReapeatabilityTwo results, each the mean of du-plicates, obtained
46、by the same operator on different daysshould be considered suspect if they differ by more than twoplatinum-colbalt units.9.2.1.2 ReproducibilityTwo results, each the mean ofduplicates, obtained by operators in different laboratories,should be considered suspect of they differ by more than sevenplati
47、num-cobalt units.9.3 BiasThe test procedure has no bias because the valueof the test result is defined only in terms of the test method.10.11. Keywords11.1 clear liquids; color; platinum-cobalt color scale9Scharf, W. W., Ferber, K. H., and White, R. G., “Stability of Platinum-CobaltColor Standards,”
48、 Materials Research and Standards, Vol 6, No. 6, June 1966, pp.302304.10Supporting data are available fromASTM International Headquarters. RequestRR: D01-1024 and RR: D02-1007.11These precision statements are based on interlaboratory studies conducted byCommittee E-15 on Industrial Chemicals on samp
49、les of ethylene glycol andmethanol as reported in Test Methods E 202, E 346, and research reports RR:E15-28, and D01-1108.TABLE 4 Precision Values for Greater than 25 Pt-Co ColorColor (Pt-Co units) Repeatability, r Reproducibility, R25 3 1075 5 15165 7 22265 10 31385 13 41475 16 49D1209053SUMMARY OF CHANGESBiasCommittee D01.35 has identified the location of selected changes to this standard since the last issue(D 1209 00) that may impact the use of this standard.(1) Added reference to Practice E29 in 1.3 of the Scopesection.(2) Added Practice E29to list of Refe
