Resistance temperature detectors (RTDs) are temperature sensors that contain a resistor that changes resistance value as its temperature changes, basically a kind of thermistor. In this sensor, the resistor is actually a small strip of with a resistance of 100 ohms at 0C, thus the name PT100. Compared to most NTC/PTC thermistors, the PT type of RTD is much most stable and precise (but also more expensive) PT100's have been used for many years to measure temperature in laboratory and industrial processes, and have developed a reputation for accuracy ( thermocouples), repeatability, and stability. Ours RTD Sensor Amplifier with the MAX31865 breakout for use with any 2, 3 or 4 wire PT100 RTD! The MAX31865 handles all of your RTD needs, and can even compensate 3 or 4 wire RTDs for better accuracy. Connect to it with any microcontroller over SPI and read out the resistance ratio from the internal ADC. We put a 430 0.1% resistor as a reference resistor on the breakout. We have some example code that will calculate the temperature based on the resistance . We even made the breakout 5V compliant, with a 3.3V regulator and level shifting, so you can use it with any for For or microcontroller. Also comes with two 2-pin terminal blocks (for connecting to the RTD sensor) and pin header (to plug into any breadboard or perfboard). Please note: this does not include an RTD sensor! Color: purple Material: PCB Package Contents: 1 x MAX31865 Temperature Sensor Module 2 x 2-pin terminal blocks 1 x pin 1 x PT100 cable Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.