Controller

A controller is generally a piece of electronic equipment that controls the temperature in a kiln in a defined way.

This may include the provision of multiple programs for different tasks, where each program can contain a number of programmable steps.

For example

• Ramp up to garaging temperature x°C.
  • At a rate of x°C per minute.
  • hold for x hours.
• Ramp up to annealing temperature x°C.
  • At a rate of x°C per minute.
  • hold for x hours.
• Ramp down to strain point temperature x°C.
  • At a rate of x°C per minute.
  • hold for x hours.
• Ramp down to temperature x°C.
  • At a rate of x°C per minute.
  • switch off.

This makes the process of controlling a kiln much easier (and more accurate) than using a pyrometer with a manual thermostat type control.

Controllers will normally operate using PID control loops to keep the temperature in the kiln under tight control, and to avoid overshoots or offsets. Unfortunately due to the lack of configuration in many controllers, unless the controller is specifically designed for your kiln they may not control the temperature in the kiln as accurately as they could, and many can overshoot during the process of return to garaging temperature upon closing the door of the kiln after inserting a bead.