Overview
EN ISO 11844-3:2020 - published by CEN and identical to ISO 11844-3:2020 - specifies methods for measuring environmental parameters used to classify the corrosivity of indoor atmospheres for metals and alloys. Part 3 of the ISO 11844 series focuses on quantitative measurement techniques (humidity, gases, particles, deposition and air flow) that support the classification of indoor corrosion risk and selection of appropriate mitigation or material choices.
Key topics and technical requirements
- Measured parameter groups
- Humidity and temperature (including the temperature–humidity complex and condensation frequency).
- Airborne gas contaminants (measurement options and placement of instruments).
- Airborne particle contaminants (volumetric and deposit measurements - reference to PM2.5/PM10 standards).
- Dry deposition velocity and air flow (to link airborne concentrations with surface deposition and corrosion risk).
- Measurement methods described
- Continuous gas-measuring instruments for real‑time monitoring.
- Active samplers (pump-driven sampling with subsequent analysis and calculation).
- Passive samplers (diffusive or badge-type samplers with defined uptake rates).
- Gas‑deposition equipment to estimate deposition rates on surfaces.
- Volumetric particulate sampling and surface deposit sampling (referencing ISO 7708 and EN 12341 where applicable).
- Performance and procedural notes
- Guidance on placing measuring equipment and sampling duration.
- Updated detection limits and references to the ISO 16000 series for indoor air pollutant sampling strategies.
- Emphasis on pre-survey knowledge of potential pollutant sources to define the measurement strategy.
Applications and who uses this standard
EN ISO 11844-3:2020 is used by professionals who need evidence-based characterization of indoor corrosivity:
- Corrosion engineers and testing laboratories - for standardized environmental monitoring and reporting.
- Facilities and asset managers - in museums, archives, data centers, and industrial plants to protect metal artifacts, electronic equipment and infrastructure.
- Conservation scientists and museums - to assess display and storage environments and guide preventive conservation.
- HVAC and building-envelope engineers - to design ventilation and control strategies that limit corrosive atmospheres.
- Coating and materials specialists - to select materials or coatings based on measured indoor corrosivity.
Related standards
- ISO 11844 series (classification framework and specimen-based corrosion testing)
- ISO 16000 series (indoor air sampling strategies and VOC/NO2 methods)
- ISO 7708 (particle size fraction definitions)
- EN 12341 (gravimetric PM measurement for ambient particulate matter)
EN ISO 11844-3:2020 provides actionable, standardized measurement approaches for assessing indoor corrosivity - essential for risk assessment, material selection and mitigation planning in environments where metal corrosion is a concern.
