ISO/TS 21397:2021 specifies a method for determining the kinetics and yields of gaseous emissions from a specimen exposed to radiant heat in a cone calorimeter. Gas yields are determined by exposing small representative specimens to an external heat flux with or without spark ignition. The concentrations of specific gases in the effluent (smoke) are measured. In combination with calculated masses of gases, their yields from the specimen mass, mass loss or mass loss rate can be determined. This document uses Fourier-Transform Infrared (FTIR) spectroscopy as described in ISO 19702, with additional information on the test apparatus and gas analyser suitable for this specific application.