ASTM_D_6698_-_14.pdf

Designation:D669814Standard Test Method forOn-Line Measurement of Turbidity Below 5 NTU in Water1This standard is issued under the fixed designation D6698;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.Scope1.1 This test method is applicable to the on-line measure-ment of turbidity under 5 nephelometric turbidity units(NTU)in water.1.2 It is the users responsibility to ensure the validity of thistest method for waters of untested matrices.1.3 In this test method calibration standards are defined inNTU values,but other assigned turbidity units are assumed tobe equivalent.1.4 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 NTU formazinstandard is also equal to a 1 FNU(formazin nephelometricunits)standard,a 1 FNRU(formazin nephelometric ratio units)standard,and so forth.1.5 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-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD1193 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 ConduitsD3864 Guide for On-Line Monitoring Systems for WaterAnalysisD7315 Test Method for Determination of Turbidity Above 1Turbidity Unit(TU)in Static Mode2.2 Other Standards:EPA 180.1 Methods for Chemical Analysis of Water andWastes,Turbidity3GLI Method 24Hach Method 8195 Determination of Turbidity by Nephelo-metry EMMC Format4ISO 7027 Determination of Turbidity5Standard Method 2130B62.3 Other Documents:U.S.Patent 4,283,143 Patterson,James A.1981.OpticalCharacterization of a Suspension.United States Patent4,283,143,filed November 19,1979,and issued August11,1981.7U.S.Patent 4,291,980 Patterson,James A.1981.Styrene-Divinylbenzene Copolymer and Method of Manufac-turer.United States Patent 4,291,980,filed August 14,1978,and issued September 29,1981.7U.S.Patent 5,777,011 Sadar,Michael J.1998.StabilizedFormazin Composition.United States Patent 5,777,011,filed December 1,1995,and issued July 7,1998.4,83.Terminology3.1 DefinitionsFor definitions of terms used in this testmethod,refer to Terminology D1129.3.2 Definitions of Terms Specific to This Standard:1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.03 on Sampling Water andWater-Formed Deposits,Analysis of Water for Power Generation and Process Use,On-Line Water Analysis,and Surveillance of Water.Current edition approved March 15,2014.Published April 2014.Originallyapproved in 2001.Last previous edition approved in 2012 as D6698 12.DOI:10.1520/D6698-14.2For 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.3Available from United States Environmental Protection Association(EPA),Ariel Rios Bldg.,1200 Pennsylvania Ave.,NW,Washington,DC 20460,http:/www.epa.gov.4Available from Hach Company,P.O.Box 389,Loveland,CO,80539-0389,http:/.5Available from International Organization for Standardization(ISO),1 rue deVaremb,Case postale 56,CH-1211,Geneva 20,Switzerland,http:/www.iso.ch.6Available from Standard Methods for the Examination of Water andWastewater,21st Edition,American Public Health Association,Washington,DC,2005,http:/www.standardmethods.org.7Available from AMCO Clear,P.O.Box 245,Powell,OH,43065,http:/.8This document is covered by a patent.Interested parties are invited to submitinformation regarding the identification of alternatives to the ASTM InternationalHeadquarters.Your comments will receive careful consideration at a meeting of theresponsible technical committee,which you may attend.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2.1 calibration turbidity standard,na turbidity standardthat is traceable and equivalent to the reference turbiditystandard to within statistical errors;calibration turbidity stan-dards include commercially prepared 4000 NTU formazin,stabilized formazin,and styrenedivinylbenzene(SDVB).3.2.1.1 DiscussionThese standards may be used to cali-brate the instrument.Calibration standards may