The temperature is measured by thermocouples positioned outside of the working tube, one in the middle and two on the sides. The outer zones are controlled with a setpoint-offset in relation to the middle zone. This allows the heat loss at the ends of the tube to be compensated to ensure an extended zone of constant temperature (+/- 5 K).

Furnace Chamber Control 
 with temperature measurement in furnace chamber outside the working tube.

• Advantages: Thermocouple protected against damage and aggressive load, very even control, attractive price
• Disadvantage: Temperature difference between displayed temperature on the controller and inside the tube

Extension Package for Furnace Chamber Control

• with additional temperature measurement in the working tube and display of the measured temperature

• Advantages: Very precise and rapid control adjustment
• Disadvantage: Costs

Only the furnace chamber temperature is measured and controlled. Regulation is carried out slowly to avoid out-of-range values. As the charge temperature is not measured and controlled, it may vary a few degrees from the chamber temperature.

If the charge control is switched on, both the charge temperature and furnace chamber temperature are measured. By setting different parameters the heat-up and cooling processes can be individually adapted. This results in a more precise temperature control at the charge.