SIST EN ISO 6142-1:2015 PDF

Overview

EN ISO 6142-1:2015 (ISO 6142-1:2015) - "Gas analysis - Preparation of calibration gas mixtures - Part 1: Gravimetric method for Class I mixtures" defines a gravimetric, traceable method for preparing calibration gas mixtures in cylinders. The standard specifies how to determine the amount-of-substance fraction (amount fraction) for one or more components, and how to calculate the associated measurement uncertainty. It applies to gaseous or totally vaporized components introduced in gas or liquid form and covers both binary and multi-component mixtures, including natural-gas type mixtures.

Key topics and technical requirements

• Gravimetric preparation: Procedures for mass-based preparation of calibration gas mixtures to achieve traceable composition values.
• Uncertainty calculation: Methodology to evaluate contributions to uncertainty from:
  • weighing process,
  • purity and quantified impurities of parent gases/ liquids,
  • mixture stability over its intended lifetime,
  • verification of the final mixture.
• Verification: Class I mixtures require individual verification of each cylinder to support low uncertainty claims.
• Applicability constraints:
  • Only for gaseous or fully vaporized components (liquid introduction is addressed in annexes),
  • Not intended for components that react unintentionally with each other or with container materials,
  • Does not cover batch production of multiple mixtures in a single process.
• Stability and homogeneity assessment: Requirements to estimate maximum storage life and assess homogeneity and stability statistically.
• Supporting guidance: Informative annexes include weighing precautions, practical examples, filling-pressure guidelines to avoid condensation, atomic weights, and mathematical derivations for uncertainty and sensitivity coefficients.

Applications

• Production of high-quality calibration gas mixtures for laboratories, field instruments, and reference standards.
• Calibration gases for environmental monitoring, emissions measurement, atmospheric research, natural gas analysis, and process control in petrochemical industries.
• Basis for certificates of analysis when issuing traceable calibration gas cylinders.

Who should use this standard

• Metrology institutes and national measurement laboratories
• Accredited calibration gas manufacturers and gas suppliers
• Analytical and environmental testing laboratories
• Instrument manufacturers and calibration service providers
• Regulatory bodies and quality managers specifying traceable calibration gases

Related standards

• ISO 6142 (general series) - this Part 1 supersedes earlier editions of ISO 6142 and is the reference for Class I mixtures. A future part will address gravimetric methods for Class II mixtures. EN adoption: EN ISO 6142-1:2015.