GMS-2000 Goniophotometer

A goniophotometer measures angular distribution of light intensity of a luminaire. From small LED modules to large luminaires, a variety of devices can be evaluated using a goniophotometer. Luminous Intensity Distribution, Beam Angle as well as Total Luminous Flux can be directly measured. GMS-2000 meets all requirements of IES LM-79 for absolute photometry of LED luminaires. Relative photometry of conventional luminaires can also be measured. While ensuring high accuracy and reproducibility, the GMS-2000 is easy to use and provides fast acquisition.

Standards Compliant

Standards such as IESNA LM-79 specify the luminaire under test to be operated in the same orientation of normal operational orientation and not moved during measurement.  GMS-2000 fully complies with the standards

Multiple Baffles

Multiple baffles with progressively decreasing diameter virtually eliminates all stray lights to improve the measurement accuracy while simultaneously minimizing air draft


GMS-2000 comes standard with filter photometer as detector.  For performing spectral measurement, the instrument can be ordered with a spectrometer with high-speed acquisition.


GMS-2000 is a Type-C goniophotometer. There are two rotation axes in GMS-2000 goniophotometer. A precision reflecting mirror rotates around the horizontal axle and the tested luminaire rotates in the prescribed burning position and around the vertical axle, while, a synchronous axle will rotate toward the opposite direction. The combined motion of the luminaire and mirror permit light measurement at the direction of any horizontal or vertical angle without tilting the tested luminaire, therefore, the luminous intensity can be measured stably and accurately. The photometer head located at a fixed position of the required photometric distance in front of the reflecting mirror to detect luminous intensity in each direction.


  • Thermostatic Photodetector:Fine V(lambda) ,CIE-f1′ less than 0.015 (Combined with mirrors)
  • Photometric resolution: 0.00001lx, 0.0001lx, 0.001lx (Optional)
  • Angle Accuracy: 0.1 degree
  • Driving Angle Resolution: Y angle 0.0016 degree    C angle 0.03 degree
  • Dimension of Mirror: 1.52m x2.2m (Customized)
  • Max Capacity of Tested Luminaires:    Power: AC/DC 600V/10A X 6 lines    Weight: 50kg Dimension: 1.6m
  • Motor driving diaphragm to eliminate stray light
  • Optional types for dimensions of tested luminaires: L(2.0m), M(1.6m), S(1.2m)



GMS-2200 comes pre-configured with high accuracy filter photometer.  This is suitable for measuring luminous intensity and luminous flux of all types of luminaire.  Lower cost and high speed of measurement.


Alternatively, it can be configured with a low-cost, high accuracy spectrometer to perform angular variation of spectral properties of luminaire under test.

For further details and custom configurations please contact us.