The FluxGage system measures total flux using photovoltaic cells. An array of pinholes covering the photovoltaic cells creates an effect of having many radiometers which sample the flux from the light source. Color is measured using a calibrated spectrometer connected via fiber to a diffuser located at the bottom of the system. The accuracy of color measurement using FluxGage depends therefore on how well colors are mixed in the measured light source. Because FluxGage uses a different approach than used in the integrating sphere, a comparison between the two instruments is necessary.