Testing Temperature Uniformity Across a PI Heater Surface
https://polyimide-heater-guide.wordcanopy.com/posts/polyimide-heater-installation-guide-for-flat-and-curved-surfaces
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