Maximum temperature control of a ceramic-alloy mixed resistance heater

In resistance heating processes, a temperature gradient frequently arises when the resistive element features a complex structure. The temperature derived from the Temperature Coefficient of Resistance (TCR) merely reflects the average temperature of the entire heating element, failing to accurately capture and control the variation of the maximum temperature on the heating element. Consequently, precise control over the maximum temperature of the heated material becomes challenging. In this study, the temperature gradient over the heating element during the heating process was investigated to acquire the variation law of its maximum temperature, to achieve effective control over the maximum temperature. Through heating experiments, the control parameters and temperature gradient of both the heating element and the PCB board were collected. A linear fitting was performed on these datasets to derive the control law for the maximum temperature. Experimental validation of the optimized heating strategy demonstrated that the maximum temperature can be effectively estimated.