PT100 high temperature readout

[drmdede]

Hi,

I have a PT100 temperature sensor, which is able to operate up to 650°C (and yes, I want to do that).

I found this

Adafruit MAX31865 RTD PT100 or PT1000 Amplifier

To get precision and accuracy out of your platinum (PT100 or PT1000) RTD you must use an amplifier that is designed to read the low resistance. Better yet, have an amplifier that can automatically adjust and compensate for the resistance of the connecting wires. If you're looking for a great RTD...

learn.adafruit.com

with the data sheet

https://cdn-learn.adafruit.com/assets/assets/000/037/309/original/MAX31865.pdf

My question is:
Can the MAX31865 readout the high temperatures (respectively the corresponding resistance)? Page 25 says Temp max = 125°C.
If I understand the MAX31865 correctly, there is a resistance to voltage transformation and a A/D transformation afterwards. But then, there must be a min and max temp...

Thanks for help

 

[ChrisP58]

Hi,

I have a PT100 temperature sensor, which is able to operate up to 650°C (and yes, I want to do that).

I found this

Adafruit MAX31865 RTD PT100 or PT1000 Amplifier

To get precision and accuracy out of your platinum (PT100 or PT1000) RTD you must use an amplifier that is designed to read the low resistance. Better yet, have an amplifier that can automatically adjust and compensate for the resistance of the connecting wires. If you're looking for a great RTD...

learn.adafruit.com

with the data sheet

https://cdn-learn.adafruit.com/assets/assets/000/037/309/original/MAX31865.pdf

My question is:
Can the MAX31865 readout the high temperatures (respectively the corresponding resistance)? Page 25 says Temp max = 125°C.
If I understand the MAX31865 correctly, there is a resistance to voltage transformation and a A/D transformation afterwards. But then, there must be a min and max temp...

Thanks for help

That 125°C is the maximum temperature for the MAX31865 chip itself. So you need to have it in a cooler place than where you have the RTD sensor.