Question

If the cold junction of a thermocouple is kept at $0^{\circ} C$ and the hot junction is kept at $T^{\circ} C$, then the relation between neutral temperature $\left(T_{n}\right)$ and temperature of inversion $\left(T_{i}\right)$ is

• A. $T_{n}=\frac{T_{i}}{2}$
• B. $T_{n}=2 T_{i}$
• C. $T_{n}=T_{i}-T$
• D. $T_{n}=T_{i}+T$

Answer 1

Answer: (A)

We know temperature of inversion $\left(T_{i}\right)$ is as much above the neutral temperature $\left(T_{n}\right)$ as neutral temperature is above the temperature of the cold junction $(T)$,
i.e., $T_{i}-T_{n}=T_{n}-T$ or $T_{i}=2 T_{n}-T$
But, here the cold junction is kept at $0^{\circ} C$, hence $T=0$
Thus, $T_{i}=2 T_{n}$ or $T_{n}=\frac{T_{i}}{2}$