Overview
ISO 10723:2012 - Natural gas - Performance evaluation for analytical systems specifies a standardized method to determine whether an analytical system for natural gas analysis is fit for purpose. The standard addresses how to use a specified calibration gas to either:
- define the range of gas compositions for which an analytical method meets predefined maximum errors and uncertainties, or
- quantify the errors and uncertainties when analysing gases within a defined composition range.
The method applies to systems that measure individual component amount fractions (for example gas chromatography-based systems used to calculate calorific value, density, Wobbe index and other properties).
Key topics and technical requirements
- Response functions and calibration: Establishes how to identify the instrument’s assumed and true response functions (calibration and analysis functions) and to validate them by regression against reference gas data.
- Calibration gas mixtures (CGM) and working measurement standards (WMS/CRM): Requires known composition and uncertainty of the calibration gas used routinely and explains the role of certified reference gas mixtures (CRMs) and WMSs.
- Experimental design: Specifies multi-point calibration experiments using a designed set of reference gas mixtures covering the intended measurement range, and that the experiment be performed within an interval comparable to routine calibrations.
- Uncertainty and error evaluation: Uses uncertainty principles (referencing the GUM) to calculate standard and expanded uncertainties for component amount fractions and for properties derived from composition.
- Interpretation and benchmarking: Provides procedures to determine analytical ranges, selection of hypothetical compositions for simulation, and guidance for periodic re-evaluation. Informative annexes illustrate application with on-line gas chromatography and provide benchmarking rationale.
Practical applications and users
Who benefits:
- Analytical laboratories and metrology institutes validating gas analysis systems
- Gas transmission and distribution operators verifying on-line or custody-transfer analysers
- Instrument manufacturers benchmarking and selecting calibration gas compositions
- Calibration service providers and QA teams ensuring measurement traceability and uncertainty compliance
Typical uses:
- Determining the composition ranges where a gas analyser meets performance requirements
- Quantifying measurement uncertainty for custody, billing, safety, and process control
- Optimizing calibration gas composition to minimize errors across the operating range
- Establishing periodic performance-evaluation schedules and corrective actions
Related standards
Normative references in ISO 10723:2012 include:
- ISO/IEC Guide 98-3 (GUM) - Uncertainty of measurement
- ISO 6143 - Comparison methods for calibration gas mixtures
- ISO 6974-2 - Uncertainty calculations for GC composition
- ISO 6976 - Calculation of calorific values, density and Wobbe index
Keywords: ISO 10723:2012, natural gas analysis, performance evaluation, calibration gas, measurement uncertainty, gas chromatography, certified reference gas mixture, working measurement standard.
