Physikalisch-Technische Bundesanstalt

Realization, maintenance and distribution of the units and characteristic numbers of source- and detector-based photometric and colorimetric quantities.

Research and development for novel light sources in applications for illumination (e.g. LEDs, OLEDs) and for signaling (e.g. LED-cluster, Displays) and photometer heads for integrating measurement technique as well as for their spectrally or spacely resolved complements.

Development of novel measurement procedures in photometry.

Close cooperation with the industry focused on a contemporary transfer of the developed novel methods and the resulting experience in the industrial applications.

Realization of photometric units

• SI-base unit for the luminous intensity, the candela (cd)
• Derived photometric units
  a) directed photometric quantities e.g. illuminance, luminance, photometric responsivity (measurements with the photometric bench of 40 m length)
  b) spacely distributed photometric quantities e.g. luminous flux, partial luminous flux (measurements with integrating spheres of up to 2.5 m diameter)
  
• Deriviation of photometric units

Measurement of emitted colors and characteristic quantities 

• Distribution temperature
• Tristimulus values
• Derived colorimetric characteristic quantities
  a) for "white light", e.g. (correlated) color temperature
  b) for "colored light", e.g. dominant wavelength, purity
• Determination of the values of characteristic color quantities
  

Calibration of light sources and photometers  

• Traceable to national standards of the PTB and equivalent to global reference values as transfer standards for the photometric units including the colorimetric characterization.
  

Research and development in the field of photometry

• Characterization of extended light-sources (e.g. OLEDS, Displays) by the measurement and certification of photometric and colorimetric values
  
  
• Development of measurement techniques focused on the transfer of units and characteristic numbers to industrial applications and research

• EUROMET Major Investment: 10021 “Facility for directional and spatially distributed photometric quantities“
  
  
• EUROMET: Project 811 “Traceability of luminous intensity and luminous flux using transfer standard lamps“
  
  
• EUROMET: Project 569 “Key-Comparison of Luminous Intensity (EUROMET.PR-K3a) and Luminous Flux (EUROMET.PR-K4)“
  
  
• Third party projects focused on traceability of photometric and radiometric units as well as colorimetric characteristic numbers from PTB to industries