PT100 Sensor

A PT100 is a Platinum RTD (Resistance Temperature Detector) with a resistance of 100Ω at 0°C which changes with temperature. It is suitable for applications in the temperature range of -200°C to 600°C but are more commonly used in the range -50°C to +250°C.

To use this sensor with our [Qwiic PT100 ADC](https://www.sparkfun.com/products/16770) please connect the red wires to terminals 3 & 4. Connect the white wire to terminal 2. Short the *A* and *B* pads on the [back of the Qwiic PT100 PCB](https://cdn.sparkfun.com//assets/parts/1/5/6/6/2/16770-Qwiic_Instrument_ADC_-_PT100-03.jpg). Be sure to use [Example4-3-Wire](https://github.com/sparkfun/SparkFun_ADS122C04_ADC_Arduino_Library/blob/master/examples/Qwiic_PT100_ADS122C04/Example4_3-Wire/Example4_3-Wire.ino) from within the ADS122C04 library.

How do PT100 sensors work? On four-wire sensors the red wires are connected to one end of the resistor; the white wires are connected to the other end. For three-wire, they use the same scheme: the two reds to one end; and one white to the other. Using a DMM you should see ~1 Ohm between the red wires; and ~100 Ohms between red and white.

**Documents:**

* [Datasheet](https://cdn.sparkfun.com/assets/2/4/2/1/c/PT100_DATA_SHEET.pdf)