A cylindrical heat transfer probe of diameter 12.5 mm is made of rough polished copper with a surface emissivity of ε = 0.15. The main heater is 25 mmwide and the two guard heaters are each 12 mm...

A cylindrical heat transfer probe of diameter 12.5 mm is made of rough polished copper with a surface emissivity of ε = 0.15. The main heater is 25 mmwide and the two guard heaters are each 12 mm wide. In a certain forced flow experiment in air, the heat supplied to the main heater has been measured to be 2.67±0.02 W when the surface temperature was 42.7±0.2◦ C. The air temperature was measured at 20.4±0.2◦ C. The effective background temperature is found to be the same as the air temperature. Estimate the convection heat transfer coefficient and its uncertainty.