The uncertainty of measurement of the luminous flux in an integrating sphere

This article has task to inform a reader of uncertainties of measurement in laboratory of light, especially in integrating sphere. In the first part there are mathematical descriptions of different types of uncertainties, including the methodology for their determination. The second part is focused on detailed description of particular standard uncertainties for measurement of the luminous flux in an integrating sphere. The last section provides practical calculations and results of standard uncertainties as a wavelength function.