Hi Mik,
Thanks for your response, today my temperature sensor is arriving. I was thinking of the same, however I thought that the full Wheatstone bridge would eliminate that error. I will still be checking this. Could it also be that the power source is the problem? I am now using a power bank or an android cellphone adapter to feed the power. Can it be that the power supply has a non-constant voltage? Is there a way to get a more constant supply?
Greetings,
Daniël