A device may be provided to sense an environment's present temperature. For example, a temperature probe might be used to determine a current operating temperature inside a boiler, a jet engine, or any other industrial system. One such device, referred to as a “thermistor,” uses a structure whose resistance varies in a pre-determined manner over a range of temperatures. In this case, a voltage across and/or a current flowing through the structure may be measured to determine the temperature of the structure.
Some thermistors, however, may have impractically small gain characteristics (e.g., the change in resistance may be too small over the range of temperatures that need to be sensed). Moreover, oxidation and other thermal effects may reduce the reliable life of a thermistor when operating at elevated temperatures or limit the operating range of the thermistor. For example, the behavior of the thermistor may begin to drift after prolonged use, especially at relatively high operating temperatures.
Accordingly, it may be desirable to develop a thermistor that has appropriate gain characteristics over a suitable range of temperatures, including substantially high temperatures. It also may be advantageous to develop a thermistor that is robust and reliable and that can be fabricated at a reasonable cost.