thermistor issues...

Hi all, I've recycled a thermistor from a device working with only 1 AAA battery.

Now, using the thermistor on the Arduino providing 3.3v to the thermistor and using a 10k resistor I have a temperature reading that is almost double of the current temperature.

I thought may be down the fact that I'm using double the voltage, so I simply divide the temperature by 1.8 and I get a correct value, however after several minutes the values are dropping by 10 degrees, if I reset the board the readings are correct again.

What is wrong? should I use a resistor to feed only 1.2 volts to the thermistor?

What is the resistance of the thermistor? Its not linear so you may be calculating wrong

Hi, I actually don't have any specification about the thermistor, I've recycled it from a cheap digital thermometer…

Would it be useful if I read the resistance with a multimeter knowing the ambient temperature? (or bathing it into ice?)

Yes puttin a multimeter on it would be helpful or any writing on it

ok, now I get good readings, it was a software issue, now I've cleaned up my code and I get consistent readings even after 12 hours...