Overview
EN ISO 10723:2012 - Natural gas: Performance evaluation for analytical systems (ISO 10723:2012) defines a standardized method to determine whether an analytical system for natural gas analysis is fit for purpose. The standard addresses two main uses:
- Establishing the range of gas compositions an analytical method can reliably measure (using a specified calibration gas) while meeting predefined limits on errors and measurement uncertainty.
- Evaluating the range of errors and uncertainties that occur when analysing gases within a defined composition range, using a specified calibration gas.
The scope assumes natural gas is predominantly methane with other hydrocarbons and non-combustible gases, and that analytical/calibration procedures are fully described.
Key topics and requirements
- Analytical requirements: Define acceptable uncertainty on composition and any derived physical properties (e.g., calorific value, density, Wobbe index).
- Response functions: Characterize instrument response vs. component amount fraction (calibration/analysis functions).
- Calibration strategy: Use of Calibration Gas Mixtures (CGM), Working Measurement Standards (WMS) and, where applicable, Certified Reference Gas Mixtures (CRM) for metrological traceability.
- Experimental design: Procedures to collect data for benchmarking instrument performance across composition ranges.
- Calculation procedures: Methods to compute uncertainties and propagate them into properties calculable from composition.
- Interpretation and criteria: How to decide if an analytical system meets pre-defined performance specifications; guidance on selecting hypothetical compositions for evaluation.
- Practical guidance annexes: Annex A provides a chromatography example; Annex B explains the benchmarking approach.
Practical applications and users
EN ISO 10723 is intended for organizations and professionals involved in natural gas measurement and quality control:
- Gas transmission and distribution operators ensuring reliable calorific value and quality reporting.
- Analytical laboratories validating gas chromatographs and other composition-measurement systems.
- Instrument manufacturers and integrators benchmarking analytical systems and designing calibration strategies.
- Metrology institutes and compliance bodies establishing traceable uncertainty statements and verification procedures.
- Plant commissioning teams and maintenance staff conducting initial and periodic performance evaluations or after component replacement.
Typical uses include commissioning new analysers, periodic verification to maintain measurement quality, selecting appropriate calibration gas composition, and quantifying uncertainty for contractual or regulatory reporting.
Related standards
Normative references cited in EN ISO 10723 include:
- ISO/IEC Guide 98-3 (GUM: uncertainty of measurement)
- ISO 6143 (comparison methods for calibration gas mixtures)
- ISO 6974-2 (GC determination of composition and uncertainty)
- ISO 6976 (calculation of calorific values, density, Wobbe index)
- ISO Guides on CRMs and WMS (Guide 31, Guide 34, Guide 35, Guide 99)
Keywords: ISO 10723, natural gas, analytical systems, performance evaluation, calibration gas, measurement uncertainty, gas chromatography, WMS, CRM, CGM.