ASTM F50-07
Historical Standard: ASTM F50-07 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
SUPERSEDED (see Active link, below)
ASTM F50
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 m. Particle concentrations not exceeding 3.5 10 6 particles/m 3 (100 000/ft 3 ) 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 1The 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. 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.
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 (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
U.S. Federal Standard
FederalStandardNo.20 Clean Room and Work Station Requirements, Controlled Environment Available from U.S. General Services Administration, Federal Supply Service, Standardization Division, Washington, DC 20406, http://www.gsa.gov. , Fed-Std-209E has been replaced by ISO/DIS 14644-1 and -2, but may continue to be used by mutual agreement.Other Documents
ISO14644-2 Cleanrooms and Associated Controlled Environments, Specifications for testing and monitoring to prove continued compliance with ISO 14644-1ASTM Standards
D1356 Terminology Relating to Sampling and Analysis of Atmospheres
F328 Practice for Calibration of an Airborne Particle Counter Using Monodisperse Spherical Particles
F649 Practice for Secondary Calibration of Airborne Particle Counter Using Comparison Procedures
F658 Practice for Calibration of a Liquid-Borne Particle Counter Using an Optical System Based Upon Light Extinction
Keywords
air sampling; airborne particles; particle counting; particle size distribution; particles; Atmospheric analysis; Calibration--semiconductor analysis instrumentation; Cleanrooms (materials/applications); Counting airborne particles; Dust-controlled areas; Light scattering; Particle counters/counting; Particulate contamination (aerospace environments); Pulse height; Size/size distribution analysis
ICS Code
ICS Number Code 13.040.30 (Workplace atmospheres)
DOI: 10.1520/F0050-07
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