Development of a smart temperature measurement system based on a self-calibrating thermocouple

A smart temperature measurement system was developed that consists of a commercially available self-calibrating thermocouple (a thermocouple with a high-purity, low-melting-point metal encapsulated near the thermojunction) connected to a data acquisition system with a specially designed algorithm capable of automatically detecting the calibration temperature of the self-calibrating thermocouple. A variety of self-calibrating thermocouples withstood long-term integrity testing, proving its worthiness as a front end to a smart temperature measurement system. A computer simulation program was written to explain the thermodynamic behavior of the system. Based on a literature review and simulation analysis, a method was developed to recognize which point on the melting or freezing plateau curve is the phase transition temperature of the encapsulated metal. The actual phase transition temperature is compared with the experimentally reported melting or freezing point of the encapsulated metal of the self-calibrating thermocouple to determine the magnitude of error in the thermocouple output.