ISO 13271:2012

Overview

ISO 13271:2012 specifies a standard reference method for determining PM10 and PM2.5 mass concentration in flue gas from stationary sources using two-stage virtual impactors. The method is designed for in‑stack measurements at industrial emission points and is particularly suitable for higher dust concentrations, flue gas with reactive compounds (e.g., sulfur, chlorine, nitric acid), high temperature or high humidity. The standard provides a protocol for size-selective separation of particles and gravimetric determination of PM10/PM2.5 mass concentrations, while noting that it is not applicable to measuring total dust mass concentration.

Key Topics and Requirements

• Principle: Size separation by inertia using two-stage virtual impactors to reproduce PM10/PM2.5 separation curves comparable to ambient conventions (ISO 7708).
• Two‑stage virtual impactor specification: Design requirements, nozzle geometry, cut-off diameters and separation curves, and verification procedures.
• Operating conditions: Guidance on flow rates, temperature, pressure, Reynolds and Stokes numbers, and influence of flue gas composition on performance.
• Sampling train and measuring setup: In‑stack sampling arrangement, entry nozzle, filter holders, collection and backup filters (CF1, CF2, BF).
• Measurement procedure: Pre‑treatment, isokinetic sampling considerations, sampling duration, post‑sampling handling and gravimetric weighing.
• Calculations and performance: Sample volume corrections (dry, standard conditions), detection limits, measurement uncertainty, particle losses and virtual impactor load limitations.
• Annexes: Practical support (e.g., representative sampling point selection, example impactor designs, aerosol generation for calibration, equipment lists).

Practical Applications and Users

ISO 13271:2012 is used by:

• Environmental and regulatory agencies for stack emission monitoring and compliance assessment.
• Emission testing laboratories and consultants performing in‑stack PM10/PM2.5 measurements at power plants, waste incinerators, cement kilns, steelworks and other heavy industries.
• Plant operators and environmental managers implementing emissions control verification and reporting.
• Researchers and instrument manufacturers validating virtual impactor performance and calibration.

Typical applications:

• Measuring PM10/PM2.5 mass concentrations at high dust load stacks where conventional cascade impactors are impractical.
• Sampling in environments with reactive gases or high humidity/temperature where impaction plates would cause artefacts.
• Simultaneous determination of PM10 and PM2.5 fractions for source apportionment and emission inventories.

Related Standards

• ISO 7708 - Particle size fractions definitions (ambient air conventions)
• ISO 12141 - Gravimetric methods for low concentration particulate measurement
• ISO 23210, ISO 15767, ISO 80000-11 - referenced for terms, particle behavior and measurement principles

Keywords: ISO 13271, PM10, PM2.5, virtual impactor, in‑stack measurements, flue gas, stationary source emissions, gravimetric method, separation curves, sampling train.