Overview
EN ISO 16911-2:2013 - "Stationary source emissions - Manual and automatic determination of velocity and volume flow rate in ducts - Part 2: Automated measuring systems" (CEN/ISO) specifies requirements for automated measuring systems (AMS) used to determine volume flow rate in ducted gaseous streams. Developed primarily for waste incinerators and large combustion plants, the standard complements the manual reference method in ISO 16911-1 and links with the QA framework in EN 14181 to ensure flow monitoring with a defined and minimized uncertainty.
Key topics and requirements
- Scope and principle: Defines purpose and relationship to EN 14181 and ISO 16911-1; focuses on reducing systematic errors in AMS flow measurements.
- Quality assurance levels (QAL): Procedures for type testing and performance assessment (QAL1), calibration and validation (QAL2), and on-going surveillance during operation (QAL3).
- Selection and installation: Criteria for choice of AMS location, mounting, ports and platforms based on pre-investigation and predictable flow profiles.
- Pre-investigation methods: Measurement-based surveys and computational fluid dynamics (CFD) to characterise flow profiles and determine measurement points/paths.
- Calibration and validation: Parallel measurements with the manual reference method, calibration functions, functional tests, transit-time tracer and other calibration options, and procedures for data evaluation.
- Uncertainty and variability: Methods to assess measurement uncertainty, calculate variability, and test the validity of calibration functions (including annual surveillance).
- Documentation and commissioning: Requirements for commissioning records, test reports and QA documentation.
Practical applications
- Continuous emissions monitoring for regulatory compliance and permitting (EU Directives referenced in the standard).
- Emission reporting and enforcement where accurate flue gas volume flow rate is required.
- Process control and optimization in combustion and industrial exhaust systems.
- Selection and validation of AMS hardware and installation designs to achieve traceable, low-uncertainty flow measurements.
Who uses this standard
- Environmental regulators and compliance auditors
- Plant operators at incinerators, power stations and large combustion plants
- CEMS/AMS manufacturers and system integrators
- Accredited testing laboratories and third‑party QA providers
- Consultants performing flow surveys, CFD modelling and QA implementation
Related standards
- ISO 16911-1 - Manual reference method for velocity and volume flow in ducts
- EN 14181 - Quality assurance of automated measuring systems (general QA framework)
- Relevant EU Directives for stationary source emissions and permitting
EN ISO 16911-2:2013 is essential for anyone specifying, installing or validating automated flow monitoring systems where traceable, low‑uncertainty measurements are required.