The temperature variation of a copper$-$constantan $($Type T$)$ thermocouple e$.$m$.$f$.$ at the

junction of two dissimilar metals is:

$E(T)=16\mathrm{.}5*T+8\mathrm{.}9*{10}^{-2}*T^2+4\mathrm{.}1*{10}^{-4}*T^3-1\mathrm{.}1*{10}^{-6}*T^4$

Where e$.$m$.$f$.E(T)$ is expressed in $V,$ and junction temperature $T$ in $C.$ This equation is

valid for the range $0$ to $400C.$ Find the equation of ideal straight line. Find the

thermocouple non$-$linearity at $100C$ and as percentage of full$-$scale deflection.