The automatic temperature control of a high-temperature resistance furnace ensures that the furnace temperature remains stable within a specified range to meet the requirements of thermal treatment processes. This is achieved by automatically switching the heating source on or off, or continuously adjusting its power output according to the deviation from the target temperature.
Common Temperature Control Methods:
- Two-Position (On-Off) Control
- The simplest control method with only two states: on or off.
- When the furnace temperature falls below the set lower limit, the heating element is fully activated.
- When the furnace temperature exceeds the set upper limit, the heating element is fully turned off.
- Typically implemented using contactors.
- Three-Position Control
- Uses both upper and lower temperature limits.
- When the temperature drops below the lower limit, the heating element is fully on.
- Provides more flexibility compared to two-position control.
- Proportional (P), Proportional-Integral (PI), and Proportional-Integral-Derivative (PID) Control
- These are widely used in process control.
- The controller calculates the error between the measured furnace temperature and the target temperature, and generates control signals to adjust the heating power.
- This allows for more precise temperature regulation, minimizing overshoot and oscillation.
In essence, the automatic control system transforms temperature deviations into appropriate adjustments in heating power, ensuring consistent and accurate furnace temperature for high-quality thermal processing.