I have a thermo couple probe, with is bi-metal. it looks somthing like this at the plug side http://www.omega.com/Temperature/images/SMPW-CC_m.jpg
As you probably know there is a difference in potential between the two metals because of the temperature, meaning that if i put a multimeter of both jack terminals i will read mVolts and it will change according to temperature that the probe feels.
I was trying to measure that when connecting the (-) to arduino GND and the (+) to A0 pin. i didn't get any reading.
I didn't connect the 5V to anything because i want to measure the Volts that are being generated by the probe.
I think i probably missed something because it's obvious the circuit is not "closed", as for the mulitumeter i get fine reading.
Thanks in advance