Check the listing for details. Testo 350XL Combustion Gas Analyzer. Condition: Used. Listed at 1500.00 USD. Combustion gas analyzer (Testo 350XL) for use in air emissions monitoring and checks. Unit comes with clean probe, lots of sensor capacity (see photo), data cable (with USB converter), internal printer, carrying strap, and high strength carrying case. Has been used in grab sampling mode (versus continuous) to keep unit clean and moisture free.