Modeling a self-calibrating thermocouple for use in a smart temperature measurement system

A finite-difference computer simulation program is developed to explain the thermodynamic behavior of the self-calibrating thermocouple under varying parameters. Based on a literature review and simulation analysis, a method is developed to recognize which point on the time-temperature curve is the calibration point. A description of the model and results of parameteric studies are given. The parametric studies described show that although different factors affect the shape of the plateau differently, the initial point of the plateau, either in heating or cooling, is the calibration temperature of the self-calibrating thermocouple. The program can be a powerful tool to the thermocouple designer because it demonstrates the effects of thermojunction location and mass and heat of fusion of the encapsulated metal. It can also assist the applications engineer by showing the behavior of the thermocouple under varying conditions of heating rates and heat transfer coefficients