ASTM_D_1125_-_14.pdf

Designation:D112514Standard Test Methods forElectrical Conductivity and Resistivity of Water1This standard is issued under the fixed designation D1125;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.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 These test methods cover the determination of theelectrical conductivity and resistivity of water.The followingtest methods are included:RangeSectionsTest Method AField and Routine Laboratory10 to 200 00012 to 18Measurement of Static(Non-Flowing)SamplesS/cmTest Method BContinuous In-Line Measure5 to 200 00019 to 23mentS/cm1.2 These test methods have been tested in reagent water.Itis the users responsibility to ensure the validity of these testmethods for waters of untested matrices.1.3 For measurements below the range of these testmethods,refer to Test Method D5391.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 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:2D1066 Practice for Sampling SteamD1129 Terminology Relating to WaterD1192 Guide for Equipment for Sampling Water and Steamin Closed Conduits(Withdrawn 2003)3D1193 Specification for Reagent WaterD2186 Test Methods for Deposit-Forming Impurities inSteamD2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD3370 Practices for Sampling Water from Closed ConduitsD4519 Test Method for On-Line Determination of Anionsand Carbon Dioxide in High Purity Water by CationExchange and Degassed Cation ConductivityD5391 Test Method for Electrical Conductivity and Resis-tivity of a Flowing High Purity Water SampleE2251 Specification for Liquid-in-Glass ASTM Thermom-eters with Low-Hazard Precision Liquids3.Terminology3.1 Definitions:3.1.1 electrical conductivity,nthe reciprocal of the a-cresistance in ohms measured between opposite faces of acentimetre cube of an aqueous solution at a specified tempera-ture.3.1.1.1 DiscussionThe unit of electrical conductivity issiemens per centimetre.(The previously used units of mhos/cmare numerically equivalent to S/cm.)The actual resistance ofthe cell,Rx,is measured in ohms.The conductance,1/Rx,isdirectly proportional to the cross-sectional area,A(in cm2),andinversely proportional to the length of the path,L(in cm):1/Rx5 KA/LThe conductance measured between opposite faces of a cen-timetre cube,K,is called conductivity.Conductivity valuesare usually expressed in microsiemens/centimetre or insiemens/centimetre at a specified temperature,normally25C.3.1.2 electrical resistivity,nthe a-c resistance in ohmsmeasured between opposite faces of a centimetre cube of anaqueous solution at a specified temperature.3.1.2.1 DiscussionThe unit of electrical resistivity is ohm-centimetre.The actual resistance of the cell,Rx,is measured inohms,and is directly proportional to the length of the path,L(in cm),and inversely proportional to the cross-sectional area,A(in cm2):Rx5 RL/AThe resistance measured between opposite faces of a centi-metre cube,R,is called resistivity.Resistivity values are1These test methods are under the jurisdiction of Committee D19 on Water andare 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 Feb.1,2014.Published March 2014.Originallyapproved in 1950.Last previous edition approved in 2009 as D1125 95(2009).DOI:10.1520/D1125-14.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 usually expressed in ohmcentimetre,or in megohm centimetre,at a specified temperature,normally 25C.3.1.3 For definitions of other terms used in these methods,refer to Terminology D1129.3.2 Symbols:3.2.1 Symbols used in the equations in Sections 14 and 16are defined as follows:J=cell constant,cm1,K=conductivity at 25C,S/cm,Kx=measured conductance,S,K1=conductivity of the KCl in the reference solution at thetemperature of measurement(Table 1),S/cm,K2=conductivity of the water used to prepare t