Question

The neutral temperature of $t_n={285}^{\circ }C$ is constant for a $Cu-Fe$ thermocouple. When the cold junction is at $0^{\circ }C$, the value of inversion temperature is $t_i={570}^{\circ }C$, but if the cold junction is at ${10}^{\circ }C$, the inversion temperature $\left(t_i\right)$ will be

• A. ${550}^{\circ }C$
• B. ${560}^{\circ }C$
• C. ${570}^{\circ }C$
• D. ${580}^{\circ }C$

Answer 1

Answer: (B)

${560}^{\circ }C$

Neutral temperature, $t_n=\frac{t_i+t_c}{2}$
$\Rightarrow {285}^{\circ }=\frac{t_i+{10}^{\circ }}{2}$
${570}^{\circ }=t_i+{10}^{\circ }$
or $t_i={560}^{\circ }$.