Okay I begin to understand. So with a really stable current in the thermistor (with the advices you gave to me), the voltage around the thermistor will just have to be measured to have a good accuracy. And it will be maybe more stable than with a wheatstone bridge, without all the resistors problems. Is that right?
Last thing, you told me about calibration but I didn't find anything about PH Anderson and the tables on google, have you got another keyword please?
Thank you very much.
Sebastien L.