Thanks yes that makes more sense. It was just one of those things that could not be exactly physically correct. Like taking the logarithm of a distance. Or travelling at the "square of the speed of light" like I remember in some dodgy scifi.
Great explanation, thanks.
John Devereux schrieb:
Hello,
lets have a look a both equations and compare them.
RRTD(t) = R0[1 + At + Bt^2 + C(t ? 100°C)t^3] (for t = 0°C)
A = 3.9083 * 10^?3 °C^?1 B = ?5.775 * 10^?7 °C^?2 C = ?4.183 * 10^?12 °C^?4
The coefficents A, B and C are the same for both equations, C is used only in the first equation and C is very small. Both equations have the same result for 0 °C, R0. Because C is very small compared to A and B, C has a (small) effect only for very low temperatures.
You may use an excel sheet to calculate values of both equations for some values between 0 and -273 °C, when you compare both results, you will see the effect of C.
Bye
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