thermistor
From Glossary of Meteorology
A device with electrical resistance that varies markedly and monotonically and that possesses a negative temperature coefficient of resistivity.
The thermistors commonly used in meteorology are composed of solid semiconducting materials with resistance that decreases 4% per °C. They are constructed in a variety of sizes and may be obtained with thermal time constants of a millisecond or less. Meteorological applications include thermometers, anemometers, and bolometers.