Positive Temperature Coefficient (PTC) thermistor temperature sensors are devices that exhibit an increase in resistance in response to an increase in temperature. Thermistors produce an output signal that is relatively large and easy to measure compared to many other temperature sensor types, though their characteristics tend to be less stable and less suitable for precise temperature measurements. PTC thermistors in particular are often adapted for over-temperature detection applications, and often exhibit a distinctly nonlinear temperature-resistance relationship that makes them useful for detection of an imprecise "high" temperature condition, though poor for making accurate measurements.