ASTM F50-21
(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
5.1 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.
5.2 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.
5.3 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.
5.4 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 samp...
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/m 3 (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 ...
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This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: F50 − 21
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
ThisstandardisissuedunderthefixeddesignationF50;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope should be recognized and minimized by using a standard
methodofprimarycalibrationandbyminimizingvariabilityof
1.1 This practice covers the determination of the particle
sample acquisition procedures.
concentration, by number, and the size distribution of airborne
particlesindust-controlledareasandcleanrooms,forparticles 1.5 Sample acquisition procedures and equipment may be
in the size range of approximately 0.01 to 5.0 µm. Particle selected for specific applications based on varying cleanroom
6 3
concentrations not exceeding 3.5 × 10 particles/m class levels. Firm requirements for these selections are beyond
3
(100000⁄ft ) are covered for all particles equal to and larger thescopeofthispractice;however,samplingpracticesshallbe
than the minimum size measured. stated that take into account potential spatial and statistical
variations of suspended particles in clean rooms.
1.2 This practice uses an airborne single particle counting
device(SPC)whoseoperationisbasedonmeasuringthesignal
NOTE 2—General references to cleanroom classifications follow Fed-
eral Standard209E, latest revision. Where airborne particles are to be
produced by an individual particle passing through the sensing
characterized in dust-controlled areas that do not meet these
zone. The signal must be directly or indirectly related to
classifications, the latest revision of the pertinent specification for these
particle size.
areas shall be used.
NOTE 1—The SPC type is not specified here. The SPC can be a
1.6 Units—The values stated in SI units are to be regarded
conventional optical particle counter (OPC), an aerodynamic particle
as standard. The values given in parentheses after SI units are
sizer,acondensationnucleuscounter(CNC)operatinginconjunctionwith
providedforinformationonlyandarenotconsideredstandard.
a diffusion battery or differential mobility analyzer, or any other device
capableofcountingandsizingsingleparticlesinthesizerangeofconcern
1.7 This standard does not purport to address all of the
and of sampling in a cleanroom environment.
safety concerns, if any, associated with its use. It is the
1.3 Individuals performing tests in accordance with this
responsibility of the user of this standard to establish appro-
practiceshallbetrainedinuseoftheSPCandshallunderstand
priate safety, health, and environmental practices and deter-
its operation.
mine the applicability of regulatory limitations prior to use.
For specific hazards statements, see Section 8.
1.4 Sincetheconcentrationandtheparticlesizedistribution
1.8 This international standard was developed in accor-
of airborne particles are subject to continuous variations, the
dance with internationally recognized principles on standard-
choice of sampling probe configuration, locations, and sam-
ization established in the Decision on Principles for the
plingtimeswillaffectsamplingresults.Further,thedifferences
Development of International Standards, Guides and Recom-
in the physical measurement, electronic, and sample handling
mendations issued by the World Trade Organization Technical
systems between the various SPCs and the differences in
Barriers to Trade (TBT) Committee.
physicalpropertiesofthevariousparticlesbeingmeasuredcan
contribute to variations in the test results. These differences
2. Referenced Documents
2
2.1 ASTM Standards:
1
This practice is under the jurisdiction of ASTM Committee E21 on Space
Simulation andApplications of SpaceTechnology and is the direct responsibility of
2
Subcommittee E21.05 on Contamination. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved April 1, 2021. Published April 2021. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1965. Last previous edition approved in 2015 as F50–12(2015). DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/F0050-21. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
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F50−21
D1356Terminology Relating t
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM 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 − 12 (Reapproved 2015) F50 − 21
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. A number in parentheses indicates the year of last reapproval. A superscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. 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
6 3 3
not exceeding 3.5 × 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 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 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—General references to cleanroom classifications follow Federal Standard 209E, latest revision. Where airborne particles are to be characterized
in dust-controlled areas that do not meet these classifications, the latest revision of the pertinent specification for these areas shall be used.
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.
Current edition approved Oct. 1, 2015April 1, 2021. Published November 2015April 2021. Originally approved in 1965. Last previous edition approved in 20122015 as
F50 – 12.F50 – 12(2015). DOI: 10.1520/F0050-12R15.10.1520/F0050-21.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
F50 − 21
1.6 Units—The values stated in SI units are to be regarded as the standard. The values given in parentheses after SI units are
provided for information 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use. For specific hazards statements, see Section 8.
1.8 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Techni
...
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