A platinum resistance thermometer is placed in a duct to measure the temperature of an airflow stream. The thermometer is placed inside a cylindrical shell 6 mm in diameter which has a polished outside surface with ? = 0.08 ± 0.02. The airstream velocity is known to be 3 m/s and the pressure is 1.0 atm. The thermometer indicates a temperature of 115?C. The duct wall temperature is measured at 193?C. Calculate the true air temperature and estimate the uncertainty in this temperature. Assume that the uncertainty in the convection heat-transfer coefficient calculated with the appropriate formula from Table 8.6 is ±15 percent. Assume that the uncertainty in the resistance-thermometer measurement is ±0.03?C.
