Dew point monitoring of thermal process furnaces

Dew point monitoring is required to optimise process control in thermal process ovens. Due to the high temperatures > 600°C, sampling systems are usually used. The sampling system consists of a pump that extracts the furnace atmosphere (usually 100% N2 or a mixture of H2 and N2). To cool the sample air to sensor-compatible temperatures, the sample is cooled down to approx. 50°C via a stainless steel cooling section and fed to the sensor via the Bypass measuring chamber. Typical Dew points are < -40°Ctd.