How Thermal Mass Changes the Behavior of a PI Heater

https://heating-technology-works.lowescouponn.com/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