ISO 15900:2020

Overview

ISO 15900:2020 - Determination of particle size distribution - Differential electrical mobility analysis for aerosol particles - defines guidelines and requirements for measuring aerosol particle number size distribution using electrical mobility analysis. Commonly called differential electrical mobility analysis, the standard covers measurement systems (DMAS) and the mobility classifier element (DEMC) for particle sizes from approximately 1 nm to 1 µm. ISO 15900:2020 (second edition) refines calibration, uncertainty calculation and best practice compared with the 2009 edition. It does not specify instrument design or application‑specific technical limits, which are addressed by other ISO technical committees.

Key topics

• Measurement principle: relationship between electrical mobility and particle size; classification with a DEMC and measurement/inversion of raw data.
• System terminology: definitions for DMAS (differential mobility analysing system) and DEMC (differential electrical mobility classifier).
• Transfer functions and charge distributions: transfer function of the DEMC and charge distribution functions for bipolar/unipolar conditioners.
• Particle losses and corrections: Brownian diffusion losses, slip correction, and effects of non‑spherical particles.
• Size range considerations: guidance and good practices for measuring particles below 10 nm.
• System components and setup: pre‑conditioners, charge conditioners, DEMC, particle detectors (e.g., CPC), data acquisition and controller requirements.
• Measurement procedures: setup, pre‑measurement checks, flow/voltage/temperature/pressure considerations, data acquisition and maintenance.
• Calibration and tests: periodic tests (zero tests, flow and voltage checks), dynamic and static particle size calibration procedures, size resolution and number concentration calibration.
• Uncertainty and traceability: calculation methods for measurement uncertainty and traceability diagrams for DEMC/DMAS.
• Informative annexes: data inversion, slip correction, cylindrical DEMC, detector information, example calibration certificates, and good practice examples.

Applications and users

ISO 15900:2020 is intended for laboratories, instrument manufacturers, calibration and testing facilities, and researchers involved in:

• Aerosol science and instrumentation
• Environmental air monitoring and particulate research
• Nanotechnology particle characterization
• Automotive exhaust and on‑road particle measurements (used with application standards)
• Occupational hygiene and regulated emissions testing

Users will apply ISO 15900 to establish robust DMAS measurement procedures, perform calibrations, assess uncertainty, and document traceable particle size distributions.

Related standards

• Application‑specific requirements and test methods are provided by relevant ISO technical committees, e.g.:
  • ISO/TC 22 (road vehicle testing)
  • ISO/TC 146 (environmental measurements)
  • ISO/TC 229 (nanotechnologies)
• ISO 15900:2020 supersedes ISO 15900:2009 (first edition).