For a prescribed wavelength , measurement of the spectral

Chapter , Problem 12.46

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For a prescribed wavelength , measurement of the spectral intensity I,e(, T ) I,b of radiation emitted by a diffuse surface may be used to determine the surface temperature, if the spectral emissivity is known, or the spectral emissivity, if the temperature is known. 1 Ts (a) Defining the uncertainty of the temperature determination as dT/T, obtain an expression relating this uncertainty to that associated with the intensity measurement, dI/I. For a 10% uncertainty in the intensity measurement at 10 m, what is the uncertainty in the temperature for T 500 K? For T 1000 K? (b) Defining the uncertainty of the emissivity determination as d/, obtain an expression relating this uncertainty to that associated with the intensity measurement, dI/I. For a 10% uncertainty in the intensity measurement, what is the uncertainty in the emissivity? 12.47 Sh