ISO 2612:2023

This document describes several test methods for measuring the ammonia amount fraction in natural gas and biomethane at the trace level (µmol mol-1). The suitable handling and sampling of pressurised mixtures of ammonia in methane that are applied to several different ammonia measurement systems are described. The measurement systems are comprised of readily available commercial spectroscopic analysers that are specific to ammonia. These NH3 analysers are considered as a black box in terms of their operation, which is dependent on the instructions of the manufacturer. The document describes suitable calibration and measurement strategies to quantify ammonia in (bio)methane around and above the 10mg m-3 (14µmol mol-1) level and applies to analysis within absolute pressure ranges of 1bar – 2bar, temperatures of 0°C – 40°C and relative humidity