Air heaters are key components in several industrial processes and identifying the element's true temperature can be difficult. Thermocouple placement and type can dramatically effect temperature readings. The equipment and materials surrounding the thermocouple will wick heat away causing temperature changes. Don't assume the readings are that of the heater element. The environment plays a role. That assumption is often the cause of overshoot that shortens the lifespan of the heater element component.
Understanding the heater element construction and adapting the controls to manage its lifespan is crucial. Here are some quick pointers to help develop a heating system for sustained performance.