LED 25 - CIE 127 compliant optical probe for "Averaged LED Intensity"

The LED 25 optical probe is based on a 25mm inner diameter integrating sphere and 1cm² measurement port. Conceived as a modular system, the LED 25 can be used with distance spacers for "Averaged LED Intensity" measurements compliant with the ILED-A (316 mm) und ILED-B (100 mm) geometries. In conjunction with a spectroradiometer, photometric and radiometric measurements can be made within the spectral range 220 - 2500 nm.

The LED 25 characteristically exhibits a very homogeneous light sensitivity across the entire detector area and thus ideally fulfils the requirements of the CIE 127 recommendations. High accuracy is assured, even for LEDs with very narrow emission angles or inhomogeneous spatial radiation patterns. However, due to the light loss typical in integrating spheres, the signal sensitivity is about x25 weaker than for the measurement adapters from the LED-4xx series. The LED 25 optical probe is generally recommended for use in standards laboratories and for reference measurements.

The LED 25 is also ideally suitable for use with the LEDGON goniophotometer from Giant for determining the spatial radiation pattern and the luminous flux generated by LED modules. The accurate cosine correction in the LED 25 also means that measurement accuracy is assured even for extended light sources.


  • universally suitable for determination of:
     o Averaged LED Intensity (ILED-A und ILED-B)
     o illuminance
     o luminous flux (in conjunction with the LEDGON goniophotometer)
  • requires only a single spectral calibration for all applications