On the TÜV-tested modular flue gas probe with 180 mm long probe shaft, the flue gas path and temperature channel can be conveniently connected to the measuring instrument via a practical bayonet lock. The probe shaft is also easy to replace, thanks to the quick-change click system on the handle. The thermocouple NiCr-Ni, which is integrated in the probe shaft, enables temperature measurement up to 500 °C. In addition, a dirt filter protects the instrument and its sensors from contamination.