Can anybody advise or point me in the direction of some info regarding the measurement of resistance to calculate the temperature of a heating wire? I'm not an electrical engineer or anything btw! I would like to heat a 5m length of capillary stainless steel with a resistance of say, 30ohms. I was thinking maybe 48V so about 82W. I then want to measure and PID control the temperature of the steel by its resistance which will change with temp by PWMing a SSR. Is there a best way to measure resistance with a changing voltage? I can do the PID control with the arduino, just want to know how to approach the resistance measuring part.
Any help much appreciated