ISO/TC 24/SC 4/WG 9 - Single particle light interaction methods

This document describes a calibration and verification method for a light extinction liquid-borne particle counter (LELPC), which is used to measure the size and particle number concentration of particles suspended in liquid. The light extinction method described in this document is based on single particle measurements. The typical size range of particles measured by this method is between 1 µm and 100 µm in particle size. The method is applicable to instruments used for the evaluation of the cleanliness of pharmaceutical products (e.g. injections, water for injections, infusions), as well as the measurement of number and size distribution of particles in various liquids. The following are within the scope of this document: — size setting error; — counting efficiency; — size resolution; — maximum particle number concentration; — sampling flow rate error; — sampling time error; — sampling volume error; — calibration interval; — reporting results from test and calibration.

This document describes a calibration and verification method for a light scattering liquid-borne particle counter (LSLPC), which is used to measure the size and particle number concentration of particles suspended in liquid. The light scattering method described in this document is based on single particle measurements. The typical size range of particles measured by this method is between 0,1 µm and 10 µm in particle size. The method is applicable to instruments used for the evaluation of the cleanliness of pure water and chemicals, as well as the measurement of number and size distribution of particles in various liquids. The measured particle size using the LSLPC depends on the refractive index of particles and medium; therefore, the measured particle size is equivalent to the calibration particles in pure water. The following are within the scope of this document: — size setting error; — counting efficiency; — size resolution; — false count; — maximum particle number concentration; — sampling flow rate error; — sampling time error; — sampling volume error; — calibration interval; — reporting results from test and calibration.

This document describes a calibration and verification method for a light scattering airborne particle counter (LSAPC), which is used to measure the size distribution and particle number concentration of particles suspended in air. The light scattering method described in this document is based on single particle measurements. The typical size range of particles measured by this method is between 0,1 μm and 10 μm in particle size. Instruments that conform to this document are used for the classification of air cleanliness in cleanrooms and associated controlled environments in accordance with ISO 14644‑1 and ISO 14644‑2, as well as the measurement of number and size distribution of particles in various environments. The following parameters are within the scope of this document: — size setting error; — counting efficiency; — size resolution; — false count; — maximum particle number concentration; — sampling flow rate error; — sampling time error; — response rate; — calibration interval; — reporting results from test and calibration.

ISO 21501-1:2009 specifies characteristics of a light scattering aerosol spectrometer (LSAS) which is used for measuring the size, number concentration and number/size distribution of particles suspended in a gas. The light scattering technique described in this document is based upon single particle measurements. The size range of particles measured by this method is between approximately 0,06 µm to 45 µm in diameter. Instruments that conform to ISO 21501-1:2009 are used for the determination of the particle size distribution and particle number concentration at relatively high concentrations of up to 1011 particles/m3. Application fields include: characterization of metered dose inhalers (MDI), dry powder inhalers (DPI) and nebulizers in pharmacy; production control of active agents; cut-off determination: impactors, cyclones and impingers; atmospheric aerosols: bio-aerosols, stables/composting facilities, nebulized droplets, measurements in street tunnels; fractional separation efficiency determination of filters. For the above-mentioned applications, aerosol spectrometers should determine the particle size distribution, particle number concentration, size resolution and sizing accuracy as accurately as possible. These aerosol spectrometers are not suitable for the classification of clean rooms.

ISO 21501-2:2007 describes a calibration and verification method for a light scattering liquid-borne particle counter (LSLPC), which is used to measure the size and particle number concentration of particles suspended in liquid. The light scattering method described in ISO 21501-2:2007 is based on single particle measurements. The typical size range of particles measured by this method is between 0,1 µm and 10 µm in particle size. Instruments that conform to ISO 21501-2:2007 are used for the evaluation of the cleanliness of pure water and chemicals, as well as the measurement of number and size distribution of particles in various liquids. The measured particle size using the LSLPC depends on the refractive index of particles and medium; therefore the measured particle size is equivalent to the calibration particles in pure water. The following are within the scope of ISO 21501-2:2007: size calibration; verification of size setting; counting efficiency; size resolution; false count rate; maximum particle number concentration; sampling flow rate; sampling time; sampling volume; calibration interval; test report.

ISO 21501-3:2007 describes a calibration and verification method for a light extinction liquid-borne particle counter (LELPC), which is used to measure the size and particle number concentration of particles suspended in liquid. The light extinction method described in ISO 21501-3:2007 is based on single particle measurements. The typical size range of particles measured by this method is between 1 µm and 100 µm in particle size. Instruments that conform to ISO 21501-3:2007 are used for the evaluation of the cleanliness of pharmaceutical products (e.g. injections, water for injections, infusions), as well as the measurement of number and size distribution of particles in various liquids. The following are within the scope of ISO 21501-3:2007: size calibration; verification of size setting; counting efficiency; size resolution; maximum particle number concentration; sampling flow rate; sampling time; sampling volume; calibration interval; test report.

ISO 21501-4:2007 describes a calibration and verification method for a light scattering airborne particle counter (LSAPC), which is used to measure the size and particle number concentration of particles suspended in air. The light scattering method described in ISO 21501-4:2007 is based on single particle measurements. The typical size range of particles measured by this method is between 0,1 µm and 10 µm in particle size. Instruments that conform to ISO 21501-4:2007 are used for the classification of air cleanliness in cleanrooms and associated controlled environments in accordance with ISO 14644-1, as well as the measurement of number and size distribution of particles in various environments. The following are within the scope of ISO 21501-4:2007: size calibration; verification of size setting; counting efficiency; size resolution; false count rate; maximum particle number concentration; sampling flow rate; sampling time; sampling volume; calibration interval; test report.