SIST EN ISO 6143:2026 PDF

Overview

EN ISO 6143:2025 (ISO 6143:2025) - "Gas analysis - Comparison methods for determining and checking the composition of calibration gas mixtures" - defines standardized comparison methods to determine and verify the composition of calibration gas mixtures by comparison with known reference gas mixtures. Published by CEN/ISO in 2025, this third edition updates procedures for regression-based analysis, uncertainty propagation and validation of analysis functions, and replaces EN ISO 6143:2006.

Key topics and technical requirements

• Comparison methods to determine the composition of a calibration gas by comparison with appropriate reference gas mixtures.
• Uncertainty calculation: propagate known uncertainties of reference gases to the derived calibration gas composition; includes guidance on exceptional uncertainties and correlated reference mixtures.
• Checking pre-assigned composition: procedures to verify supplier‑stated values by comparison with reference gases.
• Consistency testing and outlier search in suites of closely related calibration gas mixtures.
• Analysis function and validation: determination and validation of the analysis (response) function, including non‑linear response models and examination of model applicability.
• Advanced regression techniques: errors‑in‑both‑variables regression to account for uncertainties in both measurement response and reference values.
• Drift control and mismatch handling: procedures for monitoring measurement system drift and validating applicability when calibration and sample matrices differ.
• Data evaluation and reporting: recommended formats and minimum content for test reports, plus annexes with worked examples and computer implementation guidance.

Practical applications and users

This standard is essential for organizations involved in high‑quality gas metrology and calibration:

• Calibration gas producers and distributors verifying the composition of formulated gases.
• Accredited calibration and testing laboratories performing composition assignment and uncertainty assignment for calibration gases.
• Environmental, industrial and automotive laboratories that rely on traceable calibration gases for emissions, ambient monitoring and process control.
• Instrument manufacturers and metrology institutes developing calibration procedures, validation protocols and quality systems.
• Regulatory bodies and conformity assessment entities requiring traceable, documented calibration gas compositions.

Use cases include composition assignment for new calibration gas cylinders, periodic verification of supplied standards, inter‑laboratory comparisons, and detection of inconsistent or outlying gas mixtures in production batches.

Related standards and tools

• ISO 12963 (comparison methods based on one‑ and two‑point calibration)
• ISO 14912, ISO 15796 and references to the VIM for metrological terminology
• Annex C provides a computer implementation (B_LEAST) and Annex D lists alternative software and data‑evaluation guidance.

EN ISO 6143:2025 is a practical, metrologically robust framework for ensuring traceable, well‑documented composition assignments and uncertainty statements for calibration gas mixtures.