What is the time required for the center of a thermocouple junction, made of a material with thermal conductivity $($k$)$ of $30$ W m$-1$K$-1$ and density $(\backslash$rho $)$ of $8000$ kg m$-3,$ to reach $0\mathrm{.}981$ of its initial temperature difference in a turbulent water flow? The heat transfer coefficient $($h$)$ between the junction and water is $1000$ W m$-2$ K$-1,$ and the heat capacity $($Cp$)$ of the junction is $300$ J kg$-1$ K$-1.$ The junction has a diameter of $15$ mm to withstand water impact, and the analysis employs an exact solution with a one$-$term approximation using solution coefficients A$1=0\mathrm{.}03$ and $\backslash$alpha $=0\mathrm{.}6.$ The characteristic length of the junction is given by the junction radius Lc $=7\mathrm{.}5$ mm$.$