A thermocouple wire has an effective thermal conductivity of 70 W/m · ?C and is installed vertically in a solid having a thermal conductivity of 5 W/m · ?C. The thermocouple effective diameter is 2 mm and it is exposed to a convection environment at 20? with h = 125 W/m2 · ?C. The convection coefficient to the solid is 15 W/m2 · ?C. The thermocouple indicates a solid temperature of 125?C. Calculate the true temperature of the solid.