Hi.. everybody,,

This is sound like the Mathematic problem. I measure the voltage (SCXI-1121) of PT100. After I got the signal I need to calculate back to Temp.

My problem is about how to recalculate from the polynomial equation of PT100 as following

Rt=R0[1+at+bt^2+c(t-100)t^3] :

Rt : from measurement

R0 : 100 ohm

I also try with Mathlab (roots() command) and iteration but the answer has a lot of root and complex root in which it is far away from the actual temp value.

I don't know that I did is the wrong solution to get the Temp value ?

Thank you in advance for anybody help.