Photometric, radiometric and colorimetric measurements

Photometric measurements


Sedis Light Technology can rely on dedicated laboratories to carry out photometric measurements for both companies and lighting designers.

Within our laboratories we perform measurements of interior luminaires, street luminaires, prototypes and both traditional and LED light sources.

We carry out our photometric measurements with our goniophotometer Photoglobe 4FASC, class L instrument (total error <3%) for laboratory use.

We carry out radiometric and colorimetric measurements with our spectrophotometer SVRG 36-83 integrated into the Photoglobe 4FA goniophotometer.

Once the photometric procedure is completed we provide our clients with:

  • an EULUMDAT (.ldt) and/or IESNA (.ies) file
  • a .PDF measurement report file


The provided measurement report includes the following information:

a) the environmental conditions of the laboratory where the measurement has been carried out (temperature, humidity, air movement);

b) the luminaire’s stabilization time;

c) the applied standard;

d) the calculation of the luminaire’s efficiency;

e) in case an absolute measurement is performed it provides the calculation of the efficacy of the LED module and of both the system and the luminaire expressed in lm/W;

f) the electrical parameters of the luminaire;

g) color temperature;

h) the tables with the measurement values (cd/klm) on the C-Gamma planes;

i) the Polar diagram and the Cartesian diagram;

j) the light cone diagram;

k) the photo of the luminaire with indication of the photometric center.

If the luminaire’s color uniformity assessment is necessary, we provide tables containing:

  • chromaticity coordinates x, y (CIE 1931 color space)
  • chromaticity coordinates u’, v’ (CIE 1976 color space)
  • color temperature for every measurement angle on the C, Gamma planes
Spectral irradiance measured by Sedis goniophotometers


The provided measurement report includes the following information:

a) spectral irradiance in the range 360 nm – 830 nm

b) list of the following parameters displayed in table form:

  • tristimulus values X, X1, X2, Y e Z
  • chromaticity coordinates x, y (CIE1931 color space)
  • chromaticity coordinates u’, v’ (CIE1976 color space)
  • correlated color temperature (CCT)
  • chromatic rendering index (CRI)
  • chromatic difference (DC)
  • Fidelity Index
  • Gamut Index
  • total irradiance value in the range 360 nm – 830 nm

c) bar chart displaying components for the calculation of the chromatic rendering index according to the 14 color samples envisaged by the CIE standard

d) CIE1931 diagram with the Planckian locus and the indication x and y coordinates as well as their relevant values

e) CIE1976 diagram with the indication of the point corresponding to the u’ e v’ coordinates as well as their relevant values

f) Diagram of Gamut Area Index (GAI)


The above listed data are included in our MEASUREMENT REPORT.

We provide photometric measurements in a short time and at competitive costs.