Overview - ISO 25140:2010 (Methane measurement by FID)
ISO 25140:2010 specifies an automatic method for determining methane (CH4) concentration in the waste gas of stationary sources using flame ionisation detection (FID). The standard covers the principle of operation, essential performance criteria, and required quality assurance and quality control (QA/QC) procedures for continuous and intermittent measurements. It applies to methane measurements in dry or wet waste gases and is intended for permanently installed monitoring systems as well as portable or intermittent installations. The method is specific to automatic FID-based systems and does not define an independent reference method.
Key topics and technical requirements
- Measurement principle: FID quantifies organically bound carbon by ionisation in a hydrogen flame; the detector current is proportional to carbon-hydrogen bond content.
- Apparatus & sampling: Requirements for the analyser (FID) and associated sampling/extractive systems are described to ensure representative sampling from ducts and stacks.
- Performance criteria: Definition and evaluation of performance characteristics such as response time, linearity, residence time, and measurement uncertainty.
- Calibration & QA/QC: Procedures for zero/span checks, calibration with reference gases, periodic performance verification, and ongoing quality control routines.
- Measurement procedure & reporting: Standardized measurement steps, data recording and test report content to support traceability and regulatory compliance.
- Annexes and safety: Normative annexes cover operational gases, methods to determine FID performance for QA/QC, and safety measures; informative annex includes comparison test results.
Practical applications and who uses it
ISO 25140:2010 is used where reliable methane emissions data are required from stationary sources:
- Landfills, landfill gas monitoring and fugitive emissions control
- Biogas plants, anaerobic digestion and composting facilities
- Natural gas production, processing and distribution sites
- Combustion installations, biomass and waste-to-energy plants
- Environmental monitoring teams, CEMS integrators, instrument manufacturers, accredited testing laboratories, plant operators, regulators and environmental consultants
Benefits include standardized continuous emissions monitoring, improved data quality for greenhouse gas inventories, and consistent QA/QC for compliance and reporting.
Related standards
- ISO 9169, ISO 14956, ISO 20988 - referenced for performance characteristics and uncertainty estimation
- ISO 25139 - independent method for calibrating permanently installed methane measuring systems
- EN 14181, EN 15259, EN 15267-3 - complementary European standards for QA/QC and performance testing
Keywords: ISO 25140:2010, methane measurement, FID, flame ionisation detection, stationary source emissions, continuous monitoring, QA/QC, calibration, CEMS.