How should PID temperature control be specified for industrial heating elements?

Define PID control from the real duty: load mass, target temperature, permitted overshoot, heat-up time and supply voltage. These set power, sheath diameter, material, surface load, and the sensor type and mounting position that determine response speed. Check protection rating, termination, mounting geometry and insulation resistance against site conditions, since excessive surface load shortens life. Acceptance should measure heat-up curve, steady-state deviation and recovery after load change on the actual machine, recording wattage, tolerances and tuning values for future replacement.