Choosing a Control Method for a PI Heater in Automated Equipment

https://advanced-heater-source.zenbloomer.com/posts/glass-heater-technology-a-beginner-s-guide-to-transparent-heating

In sensors, a pi heater must deliver heat in a controlled way. It uses a thin resistive foil circuit laminated in polyimide film. One useful trait is fast response. Still, local hot spots can change the result