Testo 300LL Longlife Flue Gas Analyser – Precision & Efficiency for Commercial Heating System Maintenance This Winter we are offering a FREE Premium Magnetic Work Light with any testo 310 (2nd gen) Flue Gas Analyser Kit. The Testo 300LL Longlife Flue Gas Analyser is designed for precise installation, commissioning, and maintenance of commercial heating systems. Equipped with advanced O2 and CO (H2-compensated) sensors, this analyser provides accurate readings up to 30,000 ppm with an optional NO sensor for NOx measurements, which can be retrofitted as needed. Its high-quality Longlife sensors offer up to 6 years of service life, reducing the need for frequen