Overview
EN ISO 10101-2:2022 - Natural gas - Determination of water by the Karl Fischer method - Part 2: Volumetric procedure - specifies a volumetric Karl Fischer titration procedure for measuring water content in natural gas. The standard applies to water concentrations from 5 mg/m3 to 5 000 mg/m3 and expresses gas volumes at 273.15 K (0 °C) and 101.325 kPa (1 atm). This second edition (2022) updates previous editions and is intended for laboratory and field use where accurate moisture measurement in gas streams is required.
Key topics and technical requirements
- Scope and limits: volumetric Karl Fischer titration for natural gas; applicable concentration range 5–5 000 mg/m3.
- Measurement conditions: results expressed at 0 °C and 101.325 kPa (standard cubic metres).
- Principle: gas is passed through an absorption cell containing an absorbent solution; collected water is titrated with Karl Fischer (KF) reagent.
- Reagents: guidance on KF reagent (typical water equivalent ≈ 5 mg/ml), one- or two-component reagents, and preparation notes. Absorbent solution components include ethylene glycol, imidazole, sulfur dioxide and KF reagent.
- Apparatus & sampling: requirements for an absorption cell suitable for high flowrates, sampling guidance, and warnings about equipment located in hazardous areas.
- Calibration & calculation: determination of the water equivalent (titre) of KF reagent, calculation method for expressing results, and reporting format.
- Quality & uncertainty: instructions on measurement uncertainty and factors affecting accuracy.
- Interferences: references to interferences (e.g., hydrogen sulfide, mercaptans) and correction approaches described in ISO 10101-1.
Applications and users
EN ISO 10101-2:2022 is used where reliable moisture measurement in natural gas is critical:
- Natural gas producers and processing plants (production monitoring, dehydration validation)
- Transmission and distribution operators (pipeline quality control, custody transfer)
- Analytical and testing laboratories performing gas moisture analysis
- Manufacturers of gas measurement and sampling equipment
- Regulators and compliance teams verifying contractual gas quality and safety limits
Benefits include reproducible, traceable moisture data for process control, pipeline integrity, safety, custody transfer and compliance.
Related standards
- ISO 10101-1 - Introduction, principles and interferences for Karl Fischer in natural gas
- ISO 14532 - Natural gas vocabulary (terms & definitions)
- ISO 383 - Laboratory glassware (interchangeable joints)
Use these references together to ensure correct terminology, sampling practice and handling of interferences.
Keywords: EN ISO 10101-2:2022, natural gas water determination, Karl Fischer volumetric procedure, gas moisture analysis, water content in natural gas, KF titration.
