1、Designation:D121812(Reapproved 2016)Standard Test Method forRefractive Index and Refractive Dispersion of HydrocarbonLiquids1This standard is issued under the fixed designation D1218;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,th
2、e 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.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This test method covers the
3、measurement of refractiveindex,accurate to four decimal places or better,of transparentand light-colored hydrocarbons in the range of 1.3300 to1.5000 at temperatures from 20 C to 30 C by manual(optical-mechanical)or automatic(digital)procedure.1.2 The manual(optical-mechanical)procedure also coverst
4、he measurement of refractive dispersion accurate to the fourthdecimal place or better.NOTE1The test method may be suitable for measuring the refractiveindices of liquids above 1.5000 and at temperatures both below 20 C andabove 30 C;however,the test method precision may not apply.Verifi-cation of th
5、e accuracy of such measurements will depend upon theavailability of reliable,certified reference standards that demonstrate theperformance of the instrument used under the particular measuringconditions.1.3 The test method may not be applicable to liquids that arestrongly colored,or that have bubble
6、 points so near the testtemperature that a reading cannot be obtained before substan-tial weathering takes place.Liquid color should be limited toNo.4 ASTM Color or lighter,as determined by Test MethodD1500.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement
7、 are included in thisstandard.1.5 WARNINGMercury has been designated by manyregulatory agencies as a hazardous material that can causecentral nervous system,kidney and liver damage.Mercury,orits vapor,may be hazardous to health and corrosive tomaterials.Caution should be taken when handling mercury
8、andmercury containing products.See the applicable product Ma-terial Safety Data Sheet(MSDS)for details and EPAswebsitehttp:/www.epa.gov/mercury/faq.htmfor addi-tional information.Users should be aware that selling mercuryand/or mercury containing products into your state or countrymay be prohibited
9、by law.1.6This 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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced
10、 Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD1500 Test Method for ASTM Color of Petroleum Products(ASTM Color Scale)D6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceD6300 Practice for D
11、etermination of Precision and BiasData for Use in Test Methods for Petroleum Products andLubricantsE1 Specification for ASTM Liquid-in-Glass Thermometers2.2 ASTM Adjuncts:Determination of Precision and Bias Data for Use in TestMethods for Petroleum Products and Lubricants,Version4.0.6533.Terminology
12、3.1 Definitions:3.1.1 refractive dispersion,nthe difference between therefractive indices of a substance for light of two differentwavelengths,both indices being measured at the same tem-perature.3.1.1.1 DiscussionFor convenience in calculations,thevalue of the difference thus obtained is usually mu
13、ltiplied by10 000.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.04.0D on Physical and Chemical Methods.Current edition approved Oct.1,2016.Published November 2016.Originallyapprov
14、ed in 1952.Last previous edition approved in 2012 as D1218 12.DOI:10.1520/D1218-12R16.2For 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
15、 onthe ASTM website.3Out of print.No longer available from ASTM International Headquarters.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.2 refractive index,nthe ratio
16、of the velocity of light(of specified wavelength)in air,to its velocity in the substanceunder examination.3.1.2.1 DiscussionIt may also be defined as the sine of theangle of incidence divided by the sine of the angle ofrefraction,as light passes from air into the substance.This isthe relative index of refraction.If absolute refractive index(that is,referred to vacuum)is desired,this value should bemultiplied by the factor 1.00027,the absolute refractive indexof air.The numerical value of refract
