Evaluating the Resistivity-Temperature Relationship for RTDs and Other Conductors

It has long been established from experimental evidence that resistance temperature detectors (RTDs) and conductors in bulk form have an electrical resistivity that is a linear function of temperature. Although this experimental data has existed for some time, there has not been a straightforward model to explain the mechanisms leading to this relationship. In order to better understand the nature of this relationship, a microscopic model is needed so that analysis of the electrons in the material can be performed. Therefore, a theoretical framework using solid-state physics and quantum mechanics principles is presented and developed to obtain an equation for bulk conductors that relates resistivity to temperature. It is then shown that this newly developed equation produces a linear relationship for conductors and provides a very good match with experimental data obtained from platinum and nickel RTDs. Therefore, this newly developed theoretical model provides great insight into the mechanisms of experimental findings.