NTC Temperature Sensor Probe, 1M Lead, Sealed, Ez 2 Use

Details

This is an NTC (Negative Temperature Coefficient) 10k Ohm Thermistor (Temperature Sensor)

An NTC reduces in resistance as the temperature rises, and vice-versa, with 10k resistance corresponding to 25 degrees C.

Sealed metal can with a 1 meter lead, current stock has a "boot" as well (no idea why, works just the same).

Reading this (or any NTC/PTC) sensor with your micro controller is very simple, simply setup with the NTC as the upper leg of a voltage divider (Rthermistor), and a (say) 10k resistor as the lower leg (Rknown), then read the resultant voltage between them with an analog pin and knowing that you can determine the resistance...

Rthermistor = Rknown * (Vread / (Vcc-Vread))

assuming Vcc is the voltage fed to the divider circuit, Vread is the VOLTAGE read at that analog pin in the middle of the divider.

Once you have Rthermistor you can use a standard formula to calculate a close approximation of the temperature:

TemperatureC = 1 / ( (ln( Rthermistor / 10000 ) / Beta) + (1 / 298.15) ) - 273.15

For these Thermistors, Beta = 3945 (approx), note that "ln" is the natural log, in programming languages that's usually log(), in spreadsheets it's ln()