Overview
EN ISO 11665-5:2020 - Measurement of radioactivity in the environment - Air: radon‑222 - Part 5: Continuous measurement methods of the activity concentration is a CEN-endorsed ISO standard that defines how to perform continuous monitoring of radon‑222 activity concentration. It supersedes the 2015 edition and applies to air samples with radon activity concentrations greater than 5 Bq/m³. The standard is intended for assessing temporal variations of radon in open or confined atmospheres and for evaluating the influence of ventilation and meteorological conditions.
Key topics and technical requirements
The document provides structured, practical guidance and requirements covering:
- Principle of continuous radon measurement and relevant terms/definitions.
- Equipment and detector types suitable for continuous monitoring (including an informative annex on vented/current ionization chambers).
- Sampling considerations: sampling objective, installation, sampling duration, integration interval, and sampled air volume.
- Detection and measurement procedure: routine operation, data acquisition and time‑resolved recording of activity concentration.
- Influence quantities: ventilation, temperature, pressure and meteorological effects that affect temporal radon variations.
- Calibration requirements for instruments and traceability of results.
- Expression of results: reporting activity concentration, standard uncertainty, decision thresholds, detection limits and confidence intervals.
- Test report content and required metadata for validated measurements.
Practical applications
EN ISO 11665-5:2020 supports a wide range of radon monitoring needs:
- Continuous indoor and outdoor radon monitoring for environmental assessments.
- Evaluating the effectiveness of radon mitigation (ventilation changes, sealing, remediation).
- Time‑series studies to link radon levels with meteorological conditions or building occupancy patterns.
- Regulatory compliance and national surveys where temporal resolution is required (public buildings, workplaces, homes).
- Research and occupational health monitoring to quantify exposure trends and transient spikes.
Who should use this standard
- National and regional environmental and public‑health agencies
- Accredited radon measurement laboratories and service providers
- Building inspectors, facility managers and occupational safety professionals
- Researchers studying radon dynamics and mitigation performance
- Manufacturers and calibrators of radon monitoring equipment
Related keywords (SEO)
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This standard provides a practical, traceable framework for time‑resolved radon monitoring, enabling consistent data quality for protection, regulation and scientific study.
