ASTM_D_1245_-_11.pdf

Designation:D124511Standard Practice forExamination of Water-Formed Deposits by ChemicalMicroscopy1This standard is issued under the fixed designation D1245;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 practice describes a procedure for the examinationof water-formed deposits by means of chemical microscopy.This practice may be used to complement other methods ofexamination of water-formed deposits as recommended inPractices D2331 or it may be used alone when no otherinstrumentation is available or when the sample size is verysmall.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 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:2D887 Practices for Sampling Water-Formed DepositsD1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2331 Practices for Preparation and Preliminary Testing ofWater-Formed DepositsD2332 Practice for Analysis of Water-Formed Deposits byWavelength-Dispersive X-Ray FluorescenceD3483 Test Methods forAccumulated Deposition in a SteamGenerator Tube3.Terminology3.1 DefinitionsFor definitions of terms in this practicerelating specifically to water and water-formed deposits,referto Terminology D1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 Certain terms in this practice that relate specifically tochemical microscopy are described as follows:3.2.2 anisotropic,adjhaving different optical properties indifferent optical planes.3.2.2.1 DiscussionThese planes are referred to as thealpha,beta,and omega axes.3.2.3 Becke line,na faint,halo-like line that surrounds acrystal when the crystal is mounted in an oil of differentrefractive index.3.2.3.1 DiscussionThe Becke line increases in intensity asthe difference in the refractive index between the crystal andthe oil increases.3.2.4 dispersion,nthe variation of index of refraction withwavelength.3.2.5 dispersion staining,nthe color effects producedwhen a transparent object,immersed in a liquid having arefractive index near that of the object,is viewed under themicroscope by transmitted white light and precise aperturecontrol.3.2.6 extinction angle,nthe angle between the extinctionposition and some plane,edge,or line in a crystal.3.2.7 extinction position,nthe position in which an aniso-tropic crystal,between crossed polars,exhibits complete dark-ness.3.2.8 index of refraction,nthe numerical expression of theratio of the velocity of light in a vacuum to the velocity of lightin a substance.3.2.9 isotropic,adjhaving the same optical properties inall directions.3.2.10 petrographic,adjpertaining to the description ofrocks or rocklike substances.1This practice is under the jurisdiction of ASTM Committee D19 on Water andis 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 May 1,2011.Published May 2011.Originallyapproved in 1952.Last previous edition approved in 2008 as D1245 08.DOI:10.1520/D1245-11.2For 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 ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2.10.1 DiscussionSuch description is usually in terms ofmorphology and optical properties.3.2.11 solid solution,na homogeneous mixture of two ormore components,in the solid state,retaining substantially thestructure of one of the components.4.Summary of Practice4.1 The practice is essentially chemical microscopical,supplemented by optical data obtained by the petrographicmethod.The identification of compounds is made by observ-ing,under the microscope,characteristic reactions and precipi-tates resulting from the action of specific reagents on the solidsample or solutions thereof,and by measuring the opticalproperties.5.Significance and Use5.1 Chemical composition of water-formed deposits is amajor indicator of proper or improper chemical treatment ofprocess water,and is often an indicator of operational param-eters as well,for example,temperature control.This practiceallows for rapid determination of constituents present in thesedeposits,particularly those indications of improper watertreatment,since they usually have very