ASTM F50-12
(Practice)Standard Practice for Continuous Sizing and Counting of Airborne Particles in Dust-Controlled Areas and Clean Rooms Using Instruments Capable of Detecting Single Sub-Micrometre and Larger Particles
Standard Practice for Continuous Sizing and Counting of Airborne Particles in Dust-Controlled Areas and Clean Rooms Using Instruments Capable of Detecting Single Sub-Micrometre and Larger Particles
SIGNIFICANCE AND USE
The primary purpose of this practice is to describe a procedure for collecting near real-time data on airborne particle concentration and size distribution in clean areas as indicated by single particle counting techniques. Implementation of some government and industry specifications requires acquisition of particle size and concentration data using an SPC.
The processing requirements of many products manufactured in a clean room involves environmental cleanliness levels so low that a single particle counter with capability for detecting very small particles is required to characterize clean room air. Real-time information on concentration of airborne particles in size ranges from less than 0.1 μm to 5 μm and greater can be obtained only with an SPC. Definition of particles larger than approximately 0.05 μm may be carried out with direct measurement of light scattering from individual particles; other techniques may be required for smaller particles, such as preliminary growth by condensation before particle measurement.
Particle size data are referenced to the particle system used to calibrate the SPC. Differences in detection, electronic and sample handling systems among the various SPCs may contribute to differences in particle characterization. Care must be exercised in attempting to compare data from particles that vary significantly in composition or shape from the calibration base material. Variations may also occur between instruments using similar particle sensing systems with different operating parameters. These effects should be recognized and minimized by using standard methods for SPC calibration and operation.
In applying this practice, the fundamental assumption is made that the particles in the sample passing through the SPC are representative of the particles in the entire dust-controlled area being analyzed. Care is required that good sampling procedures are used and that no artifacts are produced at any point in the sample handling and ana...
SCOPE
1.1 This practice covers the determination of the particle concentration, by number, and the size distribution of airborne particles in dust-controlled areas and clean rooms, for particles in the size range of approximately 0.01 to 5.0 μm. Particle concentrations not exceeding 3.5 × 106 particles/m3 (100 000/ft3) are covered for all particles equal to and larger than the minimum size measured.
1.2 This practice uses an airborne single particle counting device (SPC) whose operation is based on measuring the signal produced by an individual particle passing through the sensing zone. The signal must be directly or indirectly related to particle size.
Note 1—The SPC type is not specified here. The SPC can be a conventional optical particle counter (OPC), an aerodynamic particle sizer, a condensation nucleus counter (CNC) operating in conjunction with a diffusion battery or differential mobility analyzer, or any other device capable of counting and sizing single particles in the size range of concern and of sampling in a cleanroom environment.
1.3 Individuals performing tests in accordance with this practice shall be trained in use of the SPC and shall understand its operation.
1.4 Since the concentration and the particle size distribution of airborne particles are subject to continuous variations, the choice of sampling probe configuration, locations and sampling times will affect sampling results. Further, the differences in the physical measurement, electronic and sample handling systems between the various SPCs and the differences in physical properties of the various particles being measured can contribute to variations in the test results. These differences should be recognized and minimized by using a standard method of primary calibration and by minimizing variability of sample acquisition procedures.
1.5 Sample acquisition procedures and equipment may be selected for specific applications based on varying...
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Designation: F50 − 12
StandardPractice for
Continuous Sizing and Counting of Airborne Particles in
Dust-Controlled Areas and Clean Rooms Using Instruments
Capable of Detecting Single Sub-Micrometre and Larger
1
Particles
ThisstandardisissuedunderthefixeddesignationF50;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.5 Sample acquisition procedures and equipment may be
selected for specific applications based on varying cleanroom
1.1 This practice covers the determination of the particle
class levels. Firm requirements for these selections are beyond
concentration, by number, and the size distribution of airborne
thescopeofthispractice;however,samplingpracticesshallbe
particlesindust-controlledareasandcleanrooms,forparticles
stated that take into account potential spatial and statistical
in the size range of approximately 0.01 to 5.0 µm. Particle
6 3 variations of suspended particles in clean rooms.
concentrations not exceeding 3.5×10 particles/m (100000/
3
ft ) are covered for all particles equal to and larger than the
NOTE 2—General references to cleanroom classifications follow Fed-
eral Standard209E, latest revision. Where airborne particles are to be
minimum size measured.
characterized in dust-controlled areas that do not meet these
1.2 This practice uses an airborne single particle counting
classifications, the latest revision of the pertinent specification for these
device(SPC)whoseoperationisbasedonmeasuringthesignal
areas shall be used.
produced by an individual particle passing through the sensing
1.6 The values stated in SI units are to be regarded as the
zone. The signal must be directly or indirectly related to
standard. The values given in parentheses are provided for
particle size.
information only and are not considered standard.
NOTE 1—The SPC type is not specified here. The SPC can be a
1.7 This standard does not purport to address all of the
conventional optical particle counter (OPC), an aerodynamic particle
safety concerns, if any, associated with its use. It is the
sizer,acondensationnucleuscounter(CNC)operatinginconjunctionwith
responsibility of the user of this standard to establish appro-
a diffusion battery or differential mobility analyzer, or any other device
priate safety and health practices and determine the applica-
capableofcountingandsizingsingleparticlesinthesizerangeofconcern
and of sampling in a cleanroom environment. bility of regulatory limitations prior to use.Forspecifichazards
statements, see Section 8.
1.3 Individuals performing tests in accordance with this
practiceshallbetrainedinuseoftheSPCandshallunderstand
2. Referenced Documents
its operation.
2
2.1 ASTM Standards:
1.4 Sincetheconcentrationandtheparticlesizedistribution
D1356Terminology Relating to Sampling and Analysis of
of airborne particles are subject to continuous variations, the
Atmospheres
choice of sampling probe configuration, locations and sam-
F328Practice for Calibration of anAirborne Particle Coun-
plingtimeswillaffectsamplingresults.Further,thedifferences
ter Using Monodisperse Spherical Particles (Withdrawn
in the physical measurement, electronic and sample handling
3
2007)
systems between the various SPCs and the differences in
F649PracticeforSecondaryCalibrationofAirborneParticle
physicalpropertiesofthevariousparticlesbeingmeasuredcan
Counter Using Comparison Procedures (Withdrawn
contribute to variations in the test results. These differences
3
2007)
should be recognized and minimized by using a standard
F658Practice for Calibration of a Liquid-Borne Particle
methodofprimarycalibrationandbyminimizingvariabilityof
Counter Using an Optical System Based Upon Light
sample acquisition procedures.
1 2
This practice is under the jurisdiction of ASTM Committee E21 on Space For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Simulation andApplications of SpaceTechnology and is the direct responsibility of contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Subcommittee E21.05 on Contamination. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved April 1, 2012. Published May 2012. Originally the ASTM website.
3
approved in 1965. Last previous edition approved in 2007 as F50–07. DOI: The last approved version of this historical standard is referenced on
10.1520/F0050-12. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
F50−12
3
Extinction (Withdrawn 2007) 3.1.6.1 Discussion—It can be quantifi
...
This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:F50–07 Designation: F50 – 12
Standard Practice for
Continuous Sizing and Counting of Airborne Particles in
Dust-Controlled Areas and Clean Rooms Using Instruments
Capable of Detecting Single Sub-Micrometre and Larger
1
Particles
This standard is issued under the fixed designation F50; the number immediately following the designation indicates the year of original
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 Thispracticecoversthedeterminationoftheparticleconcentration,bynumber,andthesizedistributionofairborneparticles
in dust-controlled areas and clean rooms, for particles in the size range of approximately 0.01 to 5.0 µm. Particle concentrations
6 3 3
not exceeding 3.5 3 10 particles/m (100 000/ft ) are covered for all particles equal to and larger than the minimum size
measured.
1.2 This practice uses an airborne single particle counting device (SPC) whose operation is based on measuring the signal
produced by an individual particle passing through the sensing zone. The signal must be directly or indirectly related to particle
size.
NOTE 1—The SPC type is not specified here. The SPC can be a conventional optical particle counter (OPC), an aerodynamic particle sizer, a
condensation nucleus counter (CNC) operating in conjunction with a diffusion battery or differential mobility analyzer, or any other device capableof
counting and sizing single particles in the size range of concern and of sampling in a cleanroom environment.
1.3 Individuals performing tests in accordance with this practice shall be trained in use of the SPC and shall understand its
operation.
1.4 Sincetheconcentrationandtheparticlesizedistributionofairborneparticlesaresubjecttocontinuousvariations,thechoice
of sampling probe configuration, locations and sampling times will affect sampling results. Further, the differences in the physical
measurement, electronic and sample handling systems between the various SPCs and the differences in physical properties of the
various particles being measured can contribute to variations in the test results. These differences should be recognized and
minimized by using a standard method of primary calibration and by minimizing variability of sample acquisition procedures.
1.5 Sample acquisition procedures and equipment may be selected for specific applications based on varying cleanroom class
levels. Firm requirements for these selections are beyond the scope of this practice; however, sampling practices shall be stated
that take into account potential spatial and statistical variations of suspended particles in clean rooms.
NOTE 2—GeneralreferencestocleanroomclassificationsfollowFederalStandard 209E,latestrevision.Whereairborneparticlesaretobecharacterized
in dust-controlled areas that do not meet these classifications, the latest revision of the pertinent specification for these areas shall be used.
1.6
1.6 ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareprovidedforinformation
only and are not considered standard.
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use. For specific hazards statements, see Section 8.
2. Referenced Documents
2
2.1 ASTM Standards:
D1356 Terminology Relating to Sampling and Analysis of Atmospheres
F328 Practice for Calibration of an Airborne Particle Counter Using Monodisperse Spherical Particles
1
This practice is under the jurisdiction of ASTM Committee E21 on Space Simulation and Applications of Space Technology and is the direct responsibility of
Subcommittee E21.05 on Contamination.
´1
Current edition approved Nov. 1, 2007. Published November 2007. Originally approved in 1965. Last previous edition approved in 2001 as F50–92(2001) DOI:
10.1520/F0050-07.
Current edition approvedApril 1, 2012. Published May 2012. Originally approved in 1965. Last previous edition approved in 2007 as F50 – 07. DOI: 10.1520/F0050-12.
2
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr
...
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