NF EN ISO 2612, X20-612 (12/2023)

This document describes several test methods for measuring the mole fraction of ammonia in natural gas and biomethane at trace levels (µmol mol-1). It describes the proper handling and sampling of pressurized mixtures of ammonia in methane applied to several different ammonia measurement systems. Measuring systems include readily available commercial spectroscopy analyzers that are specific to ammonia. These NH3 analyzers are considered a black box in terms of their operation, which depends on the manufacturer's instructions. This document describes appropriate calibration and measurement strategies for the quantification of ammonia in (bio)methane around and above the level of 10 mg m-3 (14 µmol mol-1) and applies to analysis in absolute pressure ranges of 1 bar to 2 bar, temperatures of 0°C to 40°C and relative humidity <90%. Reference is also made to additional standards that apply to either natural gas analysis or air quality measurements. In this document, the matrix gas is always methane or biomethane and the measurand is the mole fraction of NH3. NOTE 1 bar = 0.1 MPa = 105 Pa; 1 MPa = 1 N/mm2.
(Automatic translation from French)