ASTM_F_328_-_98_2003.pdf

Designation:F 328 98(Reapproved 2003)Standard Practice forCalibration of an Airborne Particle Counter UsingMonodisperse Spherical Particles1This standard is issued under the fixed designation F 328;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(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice covers procedures for calibrating anddetermining performance of an optical discrete airborne par-ticle counter(DAPC)when presented with a challenge aerosolof near-monodisperse spherical particles.The practice is di-rected towards determination of accuracy and resolution of theDAPC for particles which have entered the sampling inlet ofthe DAPC.Consideration of inlet sampling efficiency is notpart of this practice.1.2 The procedures covered here include inlet sample flowrate,zero count level,particle sizing accuracy,particle sizingresolution,particle counting efficiency,and particle concentra-tion limit.1.3 The particle size parameter that is reported is theequivalent optical diameter based on projected area of aparticle of known refractive index which is suspended in air.The minimum diameter that can be reported by a DAPC isnormally specified by the manufacturer and the maximumdiameter that can be reported for a single sample is determinedby the dynamic range of the DAPC being used.Typicalminimum diameters are in the range from approximately 0.05m to 0.5 m and a typical dynamic range specification will bebetween 10 to 1 and 50 to 1.1.4 The counting rate capability of the DAPC is limited bytemporal coincidence for the specific instrument and by themaximum counting rate capability of the electronic sizing andcounting circuitry.Coincidence is defined as the simultaneouspresence of more than one particle within the DAPC opticallydefined sensing zone at any time.The coincidence limit is astatistical function of the airborne particle concentration andthe sensing zone volume(1).2This limitation may be modifiedby the presence of particles with dimension so large as to be asignificant fraction of the sensing zone dimension(2).3Thesaturation level or maximum counting rate of the electroniccounting circuitry shall be specified by the manufacturer and isalways greater than the DAPC counting rate for the challengeaerosol used for any portion of this practice.1.5 Calibration in accordance with all parts of this practicemay not be required for routine field calibration of a DAPCunless significant changes have been noted in operation of theDAPC or major DAPC component repairs or replacementshave been made.In that situation,the DAPC should be takento a suitable metrology facility for complete calibration,following necessary repairs or modifications.Normally,theroutine field calibration may consist of determination of inletflow rate,zero count level,and particle sizing accuracy.TheDAPC functions to be calibrated shall be field or metrologyfacility calibrations shall be determined by agreement betweenpurchaser and user,but shall not exceed 12 months,unlessDAPC stability for longer periods is verified by measurementsin accordance with this practice.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:D 1193 Specification for Reagent Water4D 1356 Terminology Relating to Sampling and Analysis ofAtmospheres5E 20 Practice for Particle Size Analysis of Particulate Sub-stances in the range of 0.2 to 75 m by Optical Micros-copy6D 3195 Practice for Rotameter Calibration52.2U.S.Federal Standard:U.S.Federal Standard 209E,Airborne Particulate Cleanli-ness Classes in Cleanrooms and Clean Zones72.3Japanese1This practice is under the jurisdiction ofASTM Committee E29 on Particle andSpray Characterization and is the direct responsibility of Subcommittee E29.02 onNon-Sieving Methods.Current edition approved June 10,1998.Published December 1998.Lastprevious edition F 328-80(1998).2Jaenicke,R.,“The Optical Particle Counter:Cross Sensitivity and Coincidence:Journal of Aerosol Science Vol.3,1972,pp.95-111.3Knapp,J.Z.and Abramson,L.R.,“A New Coincidence Model for SingleParticle Counters.I.Theory and Experimental Verification”Journal of Pharmaceu-tical Science and Technology,Vol.48,1994,pp.255-294.4Annual Book of ASTM Standards,Vol 11.01.5Annual Book of ASTM Standards,Vol 11.03.6Annual Book of ASTM Standards,Vol 14.02.7Available from U.S.General Services Administration,Federal Supply ServiceStandardization Division,Washington,DC 20406.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.3.Terminology3.1 For definitions of