Plataforma para medição da condutância térmica de sensores termorresistivos.

Abstract

Thermoresistive sensors are used in feedback structures for measurement fluid velocity, radiation, and temperature. When using these sensors it is necessary to perform a prior characterization to obtain parameters such as time constant, specific heat and thermal conductance. The thermal conductance is one of the most relevant parameters essential knowledge, because it quantifies the ability of the material to exchange thermal energy with the environment. In this work, a platform for measuring the thermal conductance of termorresistivos sensors was implemented. Therefore, the thermal conductance expression for thermoresistive sensor for sensors of types PTC (Positive Temperature coeficient) and NTC (Negative Temperature coeficient) was developed. A circuit for characterization was designed. A circuit for characterization and signal processing was developed using a microcontroller that features a 10 bits A/D converter and RS-232 interface computer. The platform was used both as graphical interface and for the processing data so that it can be used by any user who needs to characterize thermoresistive sensors of PTC and NTC types.