The Testo 320 basic features all the essential functions for carrying out flue gas analysis on domestic heating systems, including flue draught, pressure measurements, and differential temperature measurement. The flue gas analyser is easy to use with its full colour graphic display featuring a user-friendly menu guidance. The analyser measures both O2 and CO (4,000ppm sensor fitted as standard) and can also display calculated parameters such as combustion ratio, CO2, etc.