1、Designation:D200812(Reapproved 2018)Standard Test Method forUltraviolet Absorbance and Absorptivity of PetroleumProducts1This standard is issued under the fixed designation D2008;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the ye
2、ar 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 test method covers the measurement of the ultra-violet absorption of a variety of petroleum products.It coversth
3、e absorbance of liquids or the absorptivity of liquids andsolids,or both,at wavelengths in the region from 220 nm to400 nm of the spectrum.1.2 The use of this test method implies that the conditions ofmeasurementwavelength,solvent(if any),sample pathlength,and sample concentrationare specified by re
4、ferenceto one of the examples of the application of this test method inthe annexes or by a statement of other conditions of measure-ment.1.3 Examples of the application of this test method are theabsorptivity of refined petroleum wax,and the absorptivity ofUSP petrolatum.1.4 The values stated in SI
5、units are to be regarded as thestandard.The values stated in Fahrenheit,feet,and inches,indicated in parentheses,are for information only.1.5 WarningMercury has been designated by many regu-latory agencies as a hazardous substance that can cause seriousmedical issues.Mercury,or its vapor,has been de
6、monstrated tobe hazardous to health and corrosive to materials.Use Cautionwhen handling mercury and mercury-containing products.Seethe applicable product Safety Data Sheet(SDS)for additionalinformation.The potential exists that selling mercury ormercury-containing products,or both,is prohibited by l
7、ocal ornational law.Users must determine legality of sales in theirlocation.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-priate safety,health,and environmental practices
8、and deter-mine the applicability of regulatory limitations prior to use.For specific warning statements,see 7.3.1,7.3.3,and 13.4.1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for t
9、heDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterE131 Terminology Relating to Molecular SpectroscopyE169 Practices for Ge
10、neral Techniques of Ultraviolet-VisibleQuantitative AnalysisE275 Practice for Describing and Measuring Performance ofUltraviolet and Visible Spectrophotometers3.Terminology3.1 Definitions of terms and symbols relating to absorptionspectroscopy in this test method shall conform to TerminologyE131.Ter
11、ms of particular significance are the following:3.2 Definitions:3.2.1 radiant energy,nenergy transmitted as electromag-netic waves.3.2.2 radiant power,P,nthe rate at which energy istransported in a beam of radiant energy.3.2.3 transmittance,T,nthe molecular property of a sub-stance that determines i
12、ts transportability of radiant power,expressed by:T 5PPo(1)where:P=the radiant power passing through the sample andPo=the radiant power incident upon the sample.3.2.4 absorbance,A,nthe molecular property of a sub-stance that determines its ability to take up radiant power,expressed by:1This test met
13、hod is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.04.0F on Absorption Spectroscopic Methods.Current edition approved Oct.1,2018.Published November 2018.Originallyapproved in 1962.Last previous edit
14、ion approved in 2012 as D2008 12.DOI:10.1520/D2008-12R18.2For 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.Copyright
15、 ASTM International,100 Barr Harbor Drive,PO Box C700,West 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 Stand
16、ards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 A 5 log101/T!5 2log10T(2)where T is the transmittance as defined in 3.2.3.3.2.4.1 DiscussionAbsorbance expresses the excess ab-sorption over that of a specified reference or standard.It isimplied that compensation has been affected for reflectancelosses,solvent absorption losses,and refractive effects,ifpresent,and that attenuation by scattering is small comparedwith attenuation by