A PT100 is a Platinum RTD（Resistance Temperature Detector）with a resistance of 100Ω at 0℃ which changes with temperature. It is suitable for applications in the temperature range of -200℃ to 600℃ but are more commonly used in the range -50℃ to +250℃.
To use this sensor with our Qwiic PT100 ADC 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. Be sure to use Example4-3-Wire 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.
Features
100Ω nominal resistance at 0℃
Temperature Coefficient（0℃ up to 100℃）：3.85 - 10-3 K-1
