1、Designation: D 5386 05Standard Test Method forColor of Liquids Using Tristimulus Colorimetry1This standard is issued under the fixed designation D 5386; 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.1. Scope*1.1 This test method covers an instrumental method for theCIE (Commission International de lEclairage) tristimulusmeasurement of the color
3、 of near-clear liquid samples. Themeasurement is converted to color ratings in the platinum-cobalt system.1.2 This test method has been found applicable to the colormeasurement of clear, liquid samples, free of haze, withnominal platinum cobalt color values in the 0 to 100 range. Itis applicable to
4、nonfluorescent liquids with light absorptioncharacteristics similar to those of the platinum cobalt colorstandard solutions. Test Methods D 1686, D 2108, and E 450deal with the visual and instrumental measurement of near-clear liquids.1.3 In determining the conformance of the test results usingthis
5、method to applicable specifications, results shall berounded in accordance with the rounding off methods ofPractice E 29.1.4 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
6、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:2D 1193 Specification for Reagent WaterD 1209 Test Method for Color of Clear Liquids (Platinum-Cobalt Scal
7、e)D 1686 Test Method for Color of Solid Aromatic Hydrocar-bons and Related Materials in the Molten State (Platinum-Cobalt Scale)D 2108 Test Method for Color of Halogenated OrganicSolvents and Their Admixtures (Platinum-Cobalt Scale)D 3437 Practice for Sampling and Handling Liquid CyclicProductsE29 P
8、ractice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE 179 Guide for Selection of Geometric Conditions forMeasurement of Reflection and Transmission Properties ofMaterialsE 308 Practice for Computing the Colors of Objects byUsing the CIE SystemE 313 Practice f
9、or Calculating Yellowness and WhitenessIndices from Instrumentally Measured Color CoordinatesE 450 Method for Measurement of Color of Low-ColoredClear Liquids Using the Hunterlab Color DifferenceMeter3E 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.
10、2 Other Document:OSHA Regulations, 29 CFR, paragraphs 1910.1000 and1910.120043. Summary of Test Method3.1 Color is measured by tristimulus values of light trans-mitted by a sample as percent of light transmitted by distilledwater. Convert the measured tristimulus values by appropriateequations to th
11、e platinum-cobalt scale.4. Significance and Use4.1 The major objective of the visual platinum-cobalt (Pt-Co) method of color measurement, as defined in Test MethodD 1209, is to rate specific materials for yellowness. Thisyellowness is frequently the result of the undesirable tendencyof liquid hydroc
12、arbons to absorb blue light due to contamina-tion in processing, storage or shipping.4.2 Clear liquids can be rated for light absorbing yellowishor brownish contaminants, using scales that simulate thelong-established visual-comparison method just cited. Whereneeded, dimensions of color can be repor
13、ted to identify anypinkness or greenness (one dimension), or grayness.5. Apparatus5.1 Instrument, with the following provisions:1This test method is under the jurisdiction of ASTM Committee D16 onAromatic Hydrocarbons and Related Chemicals and is the direct responsibility ofSubcommittee D16.04 on In
14、strumental Analysis.Current edition approved Oct. 15, 2005. Published December 2005. Originallyapproved in 1993. Last previous edition approved in 2004 as D 5386 04.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Bo
15、ok of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.4Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401.1*A Summary of Changes section appears at the en
16、d of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.1.1 Instrument Sensor, shall provide a beam for illuminat-ing the sample cell in transmission. The instrument shall becapable of converting light measured in total t
17、ransmissionthrough the sample cell to CIE X Y Z tristimulus color valuesfor the measurement conditions of CIE illuminant C and theCIE 1931 2 degree standard observer as described in GuideE 179 and Practice E 308.5.1.2 The CIE X Y Z tristimulus color values shall beconvertible to the instrumental yel
18、lowness index (YI) definedby Practice E 308 and Practice E 313. A correlation betweenmeasured yellowness index (YI) (Practice E 313) values andthe Pt-Co standard solutions shall be used to yield an equiva-lent instrumental Pt-Co rating for liquid hydrocarbon samples.5.1.3 Sample Cells, shall have cl
19、ear, colorless, parallelentrance and exit windows. Internal distance between facesshall be selectable. Path lengths from 20 to 150 mm have beenused for near-clear liquid hydrocarbons. If measuring samplesusing cells of the same path length, a path length tolerance of63 % or less would be appropriate
20、. Matched cells would bebeneficial 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 of the American Chemical So
21、ciety,where such specifications are available.5Other 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 under-stood to mean colorless d
22、istilled water, conforming to Type IVof Specification D 1193.6.3 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 chloroplatinate (K2PtCl6) and 1
23、.00 g of cobaltchloride (CoCl2H2O) in water. Carefully add 100 mL ofhydrochloric acid (HCl sp gr 1.19) and dilute to 1 L withdistilled water. The absorbance of the 500 platinum-cobaltstock solution in a cell having a 10-mm light path with distilledwater in a matched cell as the reference solution mu
24、st fallwithin the limits given in Table 1.7. Materials7.1 Platinum-Cobalt StandardsFrom the stock solutionprepare color standards in accordance with Table 2 by dilutingthe required volumes to 100 mL with water in volumetricflasks. When properly sealed and stored these standards arestable for at leas
25、t one year. 500 APHA Platinum-Cobaltstandards may also be purchased.8. Hazards8.1 Consult current OSHA regulations, suppliers MaterialSafety Data Sheets, and local regulations for all materials usedin this test method.9. Sampling and Handling9.1 Refer to Practice D 3437 for proper sampling andhandli
26、ng of liquid hydrocarbons analyzed by this test method.10. Calibration10.1 Prepare instrument for operation by following theinstrument manufacturers instructions.10.2 Use instrument standardizing adjustments or programto obtain a Pt-Co value of 0 for a sample of distilled water.10.3 It is advisable
27、to read back distilled water to verify thatthe instrument reads a Pt-Co value of 0 as an operationalqualification (OQ) step.10.4 Run QA samples to verify the analytical system is incontrol. It is desirable for the user to be able to adjust theinstrument to match the Pt-Co standard solutions as defin
28、ed in7.1.11. Procedure11.1 Check to be sure that the instrument is operating inaccordance with the manufacturers operations manual.11.2 Take three (3) instrumental readings without samplereplacement, with the average taken as being a representativePt-Co measurement of the sample. Exercise care to av
29、oidsample contamination.12. Report12.1 Report the following information:12.1.1 Sample identification, and12.1.2 Instrumental Pt-Co measurement to nearest wholeunit.5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing o
30、f 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. (USPC), Rockville,MD.TABLE 1 Absorbance Tolerance Limits for No. 500 Plati
31、num-Cobalt Stock SolutionWavelength Absorbance430 0.110 to 0.120455 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.
32、806 1.20 15 3.007 1.40 20 4.008 1.60 25 5.009 1.80 30 6.00D538605213. Precision and Bias613.1 PrecisionInstrument correlations to the Pt-Co ColorScale are based on measuring the corresponding YellownessIndex of Pt-Co liquid color standards as defined in Test MethodD 1209. However, regular samples of
33、ten exhibit a slight greenor red off-hueness or scattering haze, or both, relative to thePt-Co liquid color standards that can result in instruments ofdifferent models and manufacture reading near identical onPt-Co liquid color standards but not on samples. This precisionstatement accommodates all o
34、f the expected variables ininstrumental Pt-Co color measurement of regular samples andPt-Co liquid standards to the Pt-Co 100 level.13.1.1 A higher precision may be achieved than is listedbelow by using the same measurement method and instrumentsmodel or measuring samples, or both, that are opticall
35、y clearand are near identical in yellowness to the Pt-Co liquidstandards.13.1.2 The data for determining the precision of this testmethod are based on the analyses of o-xylene, styrene, andtoluene samples at approximate values of 2, 12, 17, 63, and 127respectively, and Pt-Co liquid standards at leve
36、ls of approxi-mately 0, 10 and 254 and 498 were also included in the roundrobin. Nineteen (19) laboratories participated in this studyusing instruments from all of the major transmission geom-etries (0:t, 8:t, 0:0) and using transmission cells of differentpath lengths (10, 20, 33, 50, 100 mm).13.2 U
37、nder the guidelines of Practice E 691, the followingcriteria should be used to judge the acceptability (95 %probability) of results obtained by this test method. The criteriawere derived from a round robin between nineteen laborato-ries. Each of the samples was run on three different days ineach lab
38、oratory.13.2.1 Intermediate Precision to Pt-Co 100 LevelBasedon an intermediate precision standard deviation of 0.44 +0.0057 (Pt-Co reading), two single test results obtained fromtwo samples of the same material in the same laboratory by thesame operator and on the same instruments in a short period
39、 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 SDY = 0.0161 X +1.23 Intermediate precision at 95 % confidence level13.2.2 Reproducibility to Pt-Co 100 Le
40、velBased 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 (Pt-Co reading).Y=mX+b Y=Reproducibility X = Platinum Cobalt Readingb = y-intercept m = slopeY =
41、0.0552 X +1.64 Reproducibility SDY = 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 thetrue value.14. Keywords14.1 APHA; Hazen; hydrocarbons; instrumental color mea-surement; Pt-Co
42、; platinum-cobalt; tristimulusSUMMARY OF CHANGESCommittee D16.04 has identified the location of selected changes to this standard since the last issue(D 5386 04) that may impact the use of this standard.(1)In1.2, extended Pt-Co color range to 100.(2) 10.3 has been added to read back water as an advi
43、sableoperational qualification (OQ) step.(3) Editorial changes have been made to 10.4 to clarifymeaning.(4) Changed precision statement in 13.1 to accommodateextension of instrumental Pt-Co Color to 100. No change wasmade to the bias statement.(5) In Section 14, added additional keywords (instrument
44、alcolor measurement, Pt-Co, APHA, Hazen) appropriate to thismethod.(6) The term repeatability is replaced by Intermediate preci-sion since the testing was done over a three day period.(7) Most labs purchase the APHA standards from vendors.This option is added in 7.1.6Supporting data are available fr
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48、ir hearing you shouldmake your views known to the ASTM Committee on Standards, 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).D5386054
