Integrating spheres, sometimes named Ulbricht spheres, are capable to measure integrated photometric quantities like total luminous or radiant flux. Similarly, average colorimetric quantities of a lighting device may be measured, either within a solid angle of 4π or 2π.  Typical applications are

  • Luminous flux measurements of light sources in production, quality control, research and development
  • Chromaticity measurements with colorimeters and spectroradiometers
  • Luminous flux calibration of working standards
  • Time-resolved light source measurement, for instance Optical Flicker


Integrating spheres with diameters of 1 m and 1.65 m and an Integrator with 2.25 m x 1.65 m for measurement of luminous flux, average chromaticity coordinates or integral radiometric properties.