Adafruit 10K Precision Epoxy Thermistor
Adafruit Product Code: 372
Need to measure something damp? This epoxy-coated precision 1% 10K thermistor is an inexpensive way to measure temperature in weather or liquids. The resistance in 25 °C is 10K (+- 1%). The resistance goes down as it gets warmer and goes up as it gets cooler. For specific temperature-to-resistance, check the lookup table.
These are often used for air conditioners, water lines, and other places where they can get damp. The PVC coating of the wires is good up to 105 °C so this isn't good for very hot stuff.
We even toss in an additional 1% 10K resistor which you can use as calibration or for a resistor divider.
We have a great detailed tutorial on how thermistors work and how to use this one best!