ASTM_D_6855_-_17.pdf

Designation:D685517Standard Test Method forDetermination of Turbidity Below 5 NTU in Static Mode1This standard is issued under the fixed designation D6855;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the 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.1.Scope*1.1 This test method covers the static determination ofturbidity in water(see 4.1).1.2 This test method is applicable to the measurement ofturbidities under 5.0 nephelometric turbidity units(NTU).1.3 This test method was tested on municipal drinkingwater,ultra-pure water,and low turbidity samples.It is theusers responsibility to ensure the validity of this test method forwaters of untested matrices.1.4 This test method uses calibration standards are definedin NTU values,but other assigned turbidity units are assumedto be equivalent.1.5 This test method assigns traceable reporting units to thetype of respective technology that was used to perform themeasurement.Units are numerically equivalent with respect tothe calibration standard.For example,a 1.0 NTU formazinstandard is also equal to a 1.0 FNU standard,a 1.0 FNRUstandard,and so forth.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 and deter-mine the applicability of regulatory limitations prior to use.Refer to the MSDSs for all chemicals used in this test method.1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD1192 Guide for Equipment for Sampling Water and Steamin Closed Conduits(Withdrawn 2003)3D1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD3370 Practices for Sampling Water from Closed ConduitsD5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Water AnalysisD7315 Test Method for Determination of Turbidity Above 1Turbidity Unit(TU)in Static ModeE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 Other Referenced Standards:U.S.EPA Method 180.1 Methods for Chemical Analysis ofWater and Wastes,Turbidity4ISO 7027 Water Qualityfor the Determination of Turbid-ity53.Terminology3.1 Definitions:3.1.1 For definitions of terms used in this standard,refer toTerminology D1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 calibration turbidity standard,na turbidity standardthat is traceable and equivalent to the reference turbiditystandard to within statistical errors.3.2.1.1 DiscussionCalibration turbidity standards includecommercially prepared 4000 NTU formazin,stabilized for-mazin(see 9.2.3),and styrenedivinylbenzene(SDVB)(see1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.07 on Sediments,Geomorphology,and Open-Channel Flow.Current edition approved Nov.1,2017.Published November 2017.Originallyapproved in 2003.Last previous edition approved in 2012 as D6855 12.DOI:10.1520/D6855-17.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from United States Environmental ProtectionAgency(EPA),WilliamJefferson Clinton Bldg.,1200 Pennsylvania Ave.,NW,Washington,DC 20460,http:/www.epa.gov.5Available from International Organization for Standardization(ISO),ISOCentral Secretariat,BIBC II,Chemin de Blandonnet 8,CP 401,1214 Vernier,Geneva,Switzerland,http:/www.iso.org.*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 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 Trade Organization Technical Barriers to Trade(TBT)Committee.1 9.2.4).These standards may be used to calibrate the instrument.Calibration standards may be instrument specific.3.2.2 calibration verification standards,ndefined stan-dards used to verify the accuracy of a calibration in themeasurement