1、Designation: D5386 16Standard Test Method forColor of Liquids Using Tristimulus Colorimetry1This standard is issued under the fixed designation D5386; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A num
2、ber 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 an instrumental method for theCIE (Commission International de lEclairage) tristimulusmeasurement of the color of
3、near-clear liquid samples. Thetransmission measurement values are converted to the colorscale in the platinum-cobalt (Pt-Co) system.1.2 This test method has been found applicable to the colormeasurement of clear, liquid samples, free of haze, withnominal Pt-Co color values in the 0 to 100 range. It
4、isapplicable to non-fluorescent liquids with light absorptioncharacteristics similar to those of the Pt-Co color standardsolutions.1.3 The tristimulus colorimetry may be calculated fromspectral measurements or be obtained directly from a colorim-eter. Practice E1455 provides some guidance on colorim
5、eters,while Test Methods D1686 and D2108 deal with the visual andinstrumental measurement of near-clear liquids.1.4 In determining the conformance of the test results usingthis method to applicable specifications, results shall berounded in accordance with the rounding off methods ofPractice E29.1.5
6、 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.6 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-p
7、riate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specific hazardstatements, see Section 8.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD1686 Test Method for Color of Solid Aromatic Hydrocar-bons and Rela
8、ted Materials in the Molten State (Platinum-Cobalt Scale)D2108 Test Method for Color of Halogenated OrganicSolvents and Their Admixtures (Platinum-Cobalt Scale)D3437 Practice for Sampling and Handling Liquid CyclicProductsD6809 Guide for Quality Control and Quality AssuranceProcedures for Aromatic H
9、ydrocarbons and Related Ma-terialsD8005 Test Method for Color of Clear Liquids (Platinum-Cobalt Scale)E29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE179 Guide for Selection of Geometric Conditions forMeasurement of Reflection and Transmission Prope
10、rtiesof MaterialsE308 Practice for Computing the Colors of Objects by Usingthe CIE SystemE313 Practice for Calculating Yellowness and WhitenessIndices from Instrumentally Measured Color CoordinatesE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE1455 P
11、ractice for Obtaining Colorimetric Data from aVisual Display Unit Using Tristimulus Colorimeters2.2 Other Document:OSHA Regulations, 29 CFR paragraphs 1910.1000 and1910.120033. Summary of Test Method3.1 The color of a liquid sample is measured as thedifference between the tristimulus values for the
12、light trans-mitted through the sample minus the tristimulus values for the1This test method is under the jurisdiction of ASTM Committee D16 onAromatic Hydrocarbons and Related Chemicals and is the direct responsibility ofSubcommittee D16.04 on Instrumental Analysis.Current edition approved Dec. 1, 2
13、016. Published January 2017. Originallyapproved in 1993. Last previous edition approved in 2010 as D5386 10. DOI:10.1520/D5386-16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume informat
14、ion, refer to the standards Document Summary page onthe ASTM website.3Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http:/www.access.gpo.gov.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, We
15、st Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World T
16、rade Organization Technical Barriers to Trade (TBT) Committee.1light transmitted through the same path length of water(Specification D1193, Type IV). The difference between thetristimulus values are used to calculate the color on the Pt-Coscale using the appropriate equations.4. Significance and Use
17、4.1 The primary objective of the visual method of Pt-Cocolor measurement, as defined in Test Method D8005, is to ratespecific materials for yellowness. This yellowness is frequentlythe result of the undesirable tendency of liquid hydrocarbons toabsorb blue light due to contamination in processing, s
18、torage orshipping.4.2 Clear liquids can be rated for light absorbing yellowishor brownish contaminants using scales that simulate thelong-established visual-comparison method.5. Apparatus5.1 Instrument, with the following provisions:5.1.1 Instrument Sensor, shall measure the light transmittedthrough
19、 a liquid sample in a cell as described in Guide E179.The instrument shall be capable of converting the measurementto CIE X Y Z tristimulus values for CIE illuminant C and theCIE 1931 2-degree standard observer as described in PracticeE308.5.1.2 The difference between the tristimulus color values fo
20、rthe sample and water shall be converted to the instrumentalyellowness index (YI) defined by Practice E313. A correlationbetween measured YI values and the Pt-Co color standardsolutions shall be used to yield an equivalent instrumentalPt-Co rating for liquid hydrocarbon samples.5.2 Sample Cells, sha
21、ll have clear, colorless, parallel en-trance and exit windows. The internal distance between thefaces shall be user selectable. Path lengths from 20 to 150 mmhave been used for near-clear liquid hydrocarbon samples.When measuring samples using cells of the same path length,a path length tolerance of
22、 63 % or less would be appropriate.Matched cells are preferred but not required.6. Reagents6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents
23、 of the American Chemical Society,where such specifications are available.4Other 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.6.2 Purity of WaterReferences to water shall be und
24、er-stood to mean clear, colorless water, conforming to Type IV ofSpecification D1193.6.3 Cobalt Chloride, (CoCl26H2O).6.4 Hydrochloric Acid (sp gr 1.19)Concentrated hydro-chloric acid (HCl).6.5 Potassium Chloroplatinate, (K2PtCl6).6.6 Platinum-Cobalt Stock SolutionDissolve 1.245 g ofpotassium chloro
25、platinate (K2PtCl6) and 1.00 g of cobaltchloride (CoCl2H2O) in water. Carefully add 100 mL ofhydrochloric acid (HCl) and dilute to 1 L with water. Theabsorbance measured for the number 500 Pt-Co stock solutionin a cell having a 10-mm path length, using a cell of the samepath length containing water
26、as the reference solution, must fallwithin the limits given in Table 1.7. Materials7.1 Platinum-Cobalt StandardsFrom the Pt-Co stocksolution, prepare color standards in accordance with Table 2 bydiluting the required volumes to 100 mL with water involumetric flasks. Pt-Co color standards with higher
27、 values canbe prepared by using proportionally greater volumes of thestock solution. When properly sealed and stored these stan-dards are stable for at least one year. Pt-Co color standards mayalso be purchased.8. Hazards8.1 Consult current OSHA regulations, suppliers SafetyData Sheets, and local re
28、gulations for all materials used in thistest method.9. Sampling and Handling9.1 Refer to Practice D3437 for proper sampling and han-dling of liquid hydrocarbon samples analyzed by this testmethod.10. Calibration10.1 Setup the instrument for operation by following themanufacturers instructions. This
29、should include setting oper-ating parameters such as the path length of the sample cells tobe used.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar
30、 Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.TABLE 1 Absorbance Tolerance Limits for Number 500 Platinum-Cobalt Stock SolutionWavelength Absorbance430 0.110 to 0.1
31、20455 0.130 to 0.145480 0.105 to 0.120510 0.055 to 0.065TABLE 2 Platinum-Cobalt Color StandardsColor StandardNumberStock Solution, mLColor StandardNumberStock Solution mL1 0.20 10 2.002 0.40 11 2.203 0.60 12 2.404 0.80 13 2.605 1.00 14 2.806 1.20 15 3.007 1.40 20 4.008 1.60 25 5.009 1.80 30 6.00D538
32、6 16210.2 Standardize the instrument using a cell of the selectedpath length containing water as the sample.10.3 Measure another sample of water in a cell of theselected path length to verify that the instrument produces aPt-Co reading of 0.10.4 Measure several Pt-Co color standards from Table 2that
33、 span the expected color range of the liquid samples in acell of the selected path length to verify the instrumentproduces the correct Pt-Co readings.NOTE 1Some instrument manufacturers may provide instructions onadjusting the instrument calibration to produce the correct Pt-Co readings.11. Procedur
34、e11.1 Verify that the instrument has been setup, standardizedand is operating in accordance with the manufacturers instruc-tions.11.2 Measure the liquid samples in a cell of the selectedpath length. Perform three (3) measurements without replacingthe sample.11.3 Calculate the average taken from the
35、three measure-ments to be the Pt-Co reading for the sample.11.4 Exercise care to avoid sample contamination.12. Report12.1 Report the following information:12.1.1 Sample identification, and12.1.2 Pt-Co reading for the sample rounded to the nearestwhole number.13. Precision and Bias513.1 PrecisionIns
36、trument correlations to the Pt-Co colorscale are based on measuring the corresponding YI of Pt-Cocolor standards as defined in Test Method D8005. However,liquid samples often exhibit a slight green or red hue, scatteringhaze, or both, relative to the Pt-Co color standards. This canresult in instrume
37、nts of different models and manufacturesreading nearly identical values for Pt-Co color standards butnot for liquid samples. This precision statement accommodatesall of the expected variables in instrumental Pt-Co colormeasurements of liquid samples and Pt-Co color standards inthe 0 to 100 range.13.
38、1.1 A higher precision than is listed below may beachieved by using the same measurement method and instru-ment model, or both. A higher precision may also be achievedby measuring samples that are optically clear and are nearidentical in YI to the Pt-Co color standards.13.1.2 The data for determinin
39、g the precision of this testmethod are from an interlaboratory study using o-xylene,styrene, and toluene samples at approximate values of 2, 12,17, 63, and 127 respectively. Pt-Co color standards at levels ofapproximately 0, 10, 254 and 498 were also used. Nineteen(19) laboratories participated in t
40、his study using instrumentswith all of the major transmission geometries (0:t, 8:t and 0:0)and using sample cells of different path lengths (10, 20, 33, 50and 100 mm). Each of the samples was run on three differentdays in each laboratory.13.2 Under the guidelines of Practice E691, the followingcrite
41、ria should be used to judge the acceptability (95 %probability) of results obtained by this test method.13.2.1 Intermediate Precision to Pt-Co 100 LevelBasedon an intermediate precision standard deviation of 0.44 +(0.0057 * Pt-Co reading), two test results obtained from twosamples of the same materi
42、al in the same laboratory by thesame operator and on the same instruments in a short period oftime should not differ by more than 1.23 + (0.0161 * Pt-Coreading).Y=mX+b Y=Intermediate precision X = Platinum Cobalt Readingb = y-intercept m = slopeY = 0.0057 X +0.44 Intermediate precision SDr = 0.0161
43、X +1.23 Intermediate precision at 95 % confidence level13.2.2 Reproducibility to Pt-Co 100 LevelBased on areproducibility standard deviation of 1.64 + (0.0552 * Pt-Coreading), two test results from samples of the same materialfrom different laboratories should not differ by more than 4.60+ (0.1546 *
44、 Pt-Co reading).Y=mX+b Y=Reproducibility X = Platinum Cobalt Readingb = y-intercept m = slopeY = 0.0552 X +1.64 Reproducibility SDR = 0.1546 X +4.60 Reproducibility at 95 % confidence level13.3 BiasThe bias of this test method cannot be deter-mined because no referee method is available to determine
45、 thetrue value.14. Quality Guidelines14.1 Laboratories shall have a quality control system inplace.14.1.1 Confirm the performance of the test instrument ortest method by analyzing a quality control sample followingthe guidelines of standard statistical quality control practices.14.1.2 A quality cont
46、rol sample is a stable material isolatedfrom the production process and representative of the samplebeing analyzed.14.1.3 When QA/QC protocols are already established inthe testing facility, these protocols are acceptable when theyconfirm the validity of test results.14.1.4 When there are no QA/QC p
47、rotocols established inthe testing facility, use the guidelines described in GuideD6809 or similar statistical quality control practices.15. Keywords15.1 APHA; Hazen; hydrocarbons; instrumental color mea-surement; Pt-Co; platinum-cobalt; tristimulus5Supporting data have been filed at ASTM Internatio
48、nal Headquarters and maybe obtained by requesting Research Report RR: RR:D16-1012. Contact ASTMCustomer Service at serviceastm.org.D5386 163ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this
49、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 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 receive careful consideration at a meeti
