Casting pot thermostats wait until the temperature is below the set point, then full power is applied until the temperature is above the set point. It then shuts off and the cycle starts over, resulting in temperature overshoot and undershoot. When used with a casting pot a PID quickly cycles the power on and off to make small adjustments to the amount of heat being generated in order to maintain the desired temperature.

MYPIN PID Temperature Controller - Demo and Parts List

MYPIN PID Temperature Controller - Building and Wiring the Controller

MYPIN PID Temperature Controller - Initial Programming, Testing, Auto-Tuning

MYPIN PID Temperature Controller - Nibbling Tool

MYPIN PID Temperature Controller - Lee 4-20 Thermocouple Options