ASTM_D_1129_-_13.pdf

Designation:D112913Standard Terminology Relating toWater1This standard is issued under the fixed designation D1129;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.absolute filter rating,nparticle size above which 100%ofparticles that are trapped on or within the filter medium.D6161absorbance,nlogarithm to the base 10 of the reciprocal ofthe transmittance(T).A=log10(1/T)=log10T.D4691absorption,nrelease for desorption holding of a substancewithin a solid by cohesive or capillary forces.D6161absorptivity,nabsorbance(A)divided by the product of thesample path length(b)and the concentration(c).a=A/bc.D4691accelerated erosion,nerosion at a rate greater than geologicor natural erosion.D4410DISCUSSIONAccelerated erosion is usually associated with anthro-pogenic activities and usually reduces plant cover and increases runoff.acceptable holding time,nany period of time less than orequal to the maximum holding time.D4841acceptable verification ratio(AVR)ratio of the differencebetween measured value of the verification sample and theknown value added to the verification sample to the squareroot of the sum of the squares of their associated combinedstandard uncertainties.See Eq.8 in 16.2.13.D7282accretion,nprocess of sediment accumulation.D4410accumulator,npulsation dampener installed on the suctionand/or discharge lines of pumps,generally plunger type,tominimize pressure surges and provide uniformity of flow.D6161accuracy,na measure of the degree of conformity of a valuegenerated by a specific procedure to the assumed or acceptedtrue value,and includes both precision and bias.accuracy,ncloseness of agreement between an observedvalue and an accepted reference value.Where an acceptedreference value is not available,accuracy is a description ofa measure of the degree of conformity of a value generatedby a specific procedure to the assumed or accepted truevalue,including both precision and bias.D6161accuracy,nmeasure of the degree of conformity of a singletest result generated by a specific procedure to the assumedor accepted true value,and includes both precision and bias.D2777accuracy,nproportion of the observed count to the truedensity of a sample.D5392accuracy,nrefers to how close a measurement is to the trueor actual value.(See Terminology D1129.)D5906acid error,nin very acid solutions,the activity of water isreduced(less than unity)causing a non-Nernstian responsein glass electrodes.Apositive error in the pH reading results.D4127acidity,nthe quantitative capacity of aqueous media to reactwith hydroxyl ions.acidity,nquantitative capacity of aqueous media to reactwith hydroxyl ions.D6161acidity,free mineral,nthe quantitative capacity of aqueousmedia to react with hydroxyl ions to pH 4.3.acidity,theoretical free mineral,nthe free mineral aciditythat would result from the conversion of the anions of strongacids in solution to their respective free acids.acoustic path,nstraight line between the centers of twoacoustic transducers.D5389acoustic path length,nface-to-face distance between trans-ducers on an acoustic path.D5389acoustic transducer,ndevice that is used to generate acous-tic signals when driven by an electric voltage,andconversely,a device that is used to generate an electricvoltage when excited by an acoustic signal.D5389acoustic travel time,ntime required for an acoustic signal topropagate along an acoustic path,either upstream ordownstream.D5389action level,nconcentration of the analyte of concern atwhich some further action is required or suggested.D68501This terminology is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.02 on Quality Systems,Specification,and Statistics.Current edition approved March 1,2013.Published April 2013.Originallyapproved in 1950.Last previous edition approved in 2010 as D1129 10.DOI:10.1520/D1129-13.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 activated carbon,ngranulated or powdered activated carbonused to remove tastes,odor,chlorine,chloramines,and someorganics from water.A family of carbonaceous substancesmanufactured by processes that develop adsorptiveproperties.D6161activity,nthermodynamically effective concentration of afree ion in solution.In dilute solutions,ionic activity andconcentration are practically identical,but in solutions ofhigh ionic strength,or in the presence of complexing agents,activity may differ significantly from concentration.Ionicactivity,not concentration,determines both the rate and theextent of chemical reactions.D4127activity coefficient,nfactor,that relates activity,A,to theconcentration,C of a species in solution:A 5 CThe activity coefficient is dependent on the ionic strengthof the solu