How to Maintain Mica Heating Plate for Stable Day-to-Day Heating
https://industrial-heating.timeforchangecounselling.com/choosing-a-mica-heater-for-your-application-a-practical-checklist
Many heating problems look like a power problem at first. In practice, the cause may be contact, heat loss, sensor position, or poor fit. A mica heating plate works best when these parts are planned together