I’m heating a ferronickel wire, and I need a reliable measurement of temperature, I was using a thermocouple to do this measurement but the wire is cooled when it’s touched by the thermocouple so now I want to estimate the temperature by the change of the wire resistance , I’m using the four-wire method to measure so it should be good enough.
Now I need to find ‘t’ from this equation
RT = R20 [ 1 + alfa (t-20)]
I found the resistivity of the ferronickel to be:
0.86 ohm mm2/m at ºC
Which is quite accurate, but I can’t find alfa
