The photometric scales for SI base unit, candela and other photometric units, lumen, lux, cd/m2, etc. are realized and maintained in Photometry Laboratory.We study measurement techniques and standards of all kinds of applications in photometry.We provide calibration service for illuminance meter, luminance meter, reference photometers, photometric and chromatic properties of lamp standards, and develop technique support for lighting, imaging...

  • Improvement of the Working Standard of Luminance

    The luminance units of NIM were established using a white reflectance standard plate illuminated by a luminous intensity standard lamp. The uncertainty is limited by determination error of the reflectance factor of a white plate. It is the main...

  • Standard of Low Level Light Illuminance

    The standard of low level light Illuminance was established at NIM in 1976 using neutral glass attenuator method. This standard has been reconstructed in this project using adjustable twin-integrating sphere source method.

International Cooperation

National Measurement Standards and CMCs

Primary Standard of Luminous Flux

Primary Standard of Luminous Intensity



  • +86-10-6452-4830 Liu Hui
  • Associate Research Fellow, Director of photometry laboratory
  • liuhui@nim.ac.cn

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