Device and method for thermally treating workpieces in particular by convective heat transfer

A device for thermally treating workpieces, in particular printed circuit boards or the like that are equipped with electrical and electronic components, comprising

• at least one process chamber in which at least one heating or cooling zone is formed or disposed, wherein
• a temperature-controlled gaseous fluid, which is heated by a heating device, can be introduced into the heating or cooling zone,
• wherein the workpieces pass through the heating or cooling zone and heat is transferred particularly in a convective manner between the workpieces and the temperature-controlled fluid, and
• comprising at least one temperature measuring element disposed in the process chamber,
• comprising at least one sensor element that has a defined mass and is disposed in the process chamber, such that
• heat is convectively transferred between the sensor element and the fluid, and
• an apparatus provided for cooling or heating the sensor element, the apparatus being separate and distinct from the heating device, wherein
• the temperature of the sensor element can be measured by the temperature measuring element.