MAX31865 PT100/PT1000 RTD Temperature Thermocouple Sensor Amplifier Board 3.3/5V Temperature Detector Module for Arduino with -50 to 200℃ 0.5m/1.6ft 3 Wires PT100 RTD Sensor Probe

This is for a PT1000, not a PT100. The listing says to use with a PT1000, you have to swap resistor to a 4301, but it is already a 4301. So basically useless if you decide to buy it to use with a PT100.

Bought this as a replacement for a BTT MAX31865 that came with my H2 500C hotend. Works just the same, you just have to make sure to get the resistors/solder bridges set properly for your application.

There's a 4.3K ohm resistor installed in Rref, which makes this board compatible with PT1000 thermocouples. It comes with two 430 ohm resistors for PT100 thermocouples. The thermocouple included is a PT100, which will not work with this board unless you remove the Rref resistor and solder one of their 430 resistors in.It doesn't make a lot of sense why they would include a PT100 and a 4.3K combination, but if you are looking for a MAX31865 board ready to go for a PT1000 thermocouple, this one will work for you.

Wired up the board and attempted to read the temperature. Tried with an Arduino uno and a couple of libraries, no luck. Measured the resistance between the two red wires, it was too low 0.2 ohms. I think it should be 2 ohms.Save your time and buy from somewhere else.

While the PT100 works fine, this boards construction is not the best. Mine came pre-used! Never seen this before when ordering parts. The 2/4 pin jumper was mangled. Looks like someone put way too much heat on it. Not sure if I got sent a someone’s returned product but I was very disappointed. I tried to salvage the board but it is not giving accurate readings…