ASTM_D_1357_-_95_2011.pdf

Designation:D135795(Reapproved 2011)Standard Practice forPlanning the Sampling of the Ambient Atmosphere1This standard is issued under the fixed designation D1357;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 The purpose of this practice is to present the broadconcepts of sampling the ambient air for the concentrations ofcontaminants.Detailed procedures are not discussed.Generalprinciples in planning a sampling program are given includingguidelines for the selection of sites and the location of the airsampling inlet.1.2 Investigations of atmospheric contaminants involve thestudy of a heterogeneous mass under uncontrolled conditions.Interpretation of the data derived from the air samplingprogram must often be based on the statistical theory ofprobability.Extreme care must be observed to obtain measure-ments over a sufficient length of time to obtain results that maybe considered representative.1.3 The variables that may affect the contaminant concen-trations are the atmospheric stability(temperature-heightprofile),turbulence,wind speed and direction,solar radiation,precipitation,topography,emission rates,chemical reactionrates for their formation and decomposition,and the physicaland chemical properties of the contaminant.To obtain concen-trations of gaseous contaminants in terms of weight per unitvolume,the ambient temperature and atmospheric pressure atthe location sampled must be known.1.4 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:2D1356 Terminology Relating to Sampling and Analysis ofAtmospheresD3249 Practice for General Ambient Air Analyzer Proce-duresD3614 Guide for Laboratories Engaged in Sampling andAnalysis of Atmospheres and EmissionsNOTE1A list of references are appended to this practice whichprovide greater details including background information,air qualitymodeling techniques,and special purposes air sampling programs(1).33.Terminology3.1 DefinitionsFor definitions of terms used in thispractice,refer to Terminology D1356.4.Summary of Practice4.1 This practice describes the general guidelines in plan-ning for sampling the ambient air for the concentrations ofcontaminants.5.Significance and Use5.1 Since the analysis of the atmosphere is influenced byphenomena in which all factors except the method of samplingand analytical procedure are beyond the control of theinvestigator,statistical consideration must be given to deter-mine the adequacy of the number of samples obtained,thelength of time that the sampling program is carried out,and thenumber of sites sampled.The purpose of the sampling and thecharacteristics of the contaminant to be measured will have aninfluence in determining this adequacy.Regular,or if possible,continuous measurements of the contaminant with simultane-ous pertinent meteorological observations should be obtainedduring all seasons of the year.Statistical techniques may thenbe applied to determine the influence of the meteorologicalvariables on the concentrations measured(2).5.2 Statistical methods may be used for the interpretation ofall of the data available(2).Trends of patterns and relation-ships between variables of statistical significance may bedetected.Much of the validity of the results will depend,however,on the comprehensiveness of the analysis and thelocation and contaminant measured.For example,if 24-hsamples of suspended particulate matter are obtained onlyperiodically(for example,every 6 or 8 days throughout the1This practice is under the jurisdiction ofASTM Committee D22 on Air Qualityand is the direct responsibility of Subcommittee D22.03 on Ambient Atmospheresand Source Emissions.Current edition approved Oct.1,2011.Published October 2011.Originallyapproved in 1955.Last previous edition approved in 2005 as D1357-95(2005).DOI:10.1520/D1357-95R11.2For 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 boldface numbers in parentheses refer to the list of references at the end ofthis practice.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 year),the geometric mean of the measured concentrations isrepresentative of the median value assuming the data are lognormally distributed.The geometric mean level may be used tocompare the air quality at different locations at which suchregular but intermittent o