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The LEDs will also degrade in intensity during their lifetime. To ensure that all measurements including the auto-
generated and standard illuminants, are correct, you must perform a spectral calibration regularly.
You must also consider the degradation of the LED when saving self-defined presets. If you save a preset with
LED channels that use its maximum intensity, the possibility exists that this intensity cannot be reached after the
burn-in time or the long-time degradation of the LED. In this case, you will get a warning message from the iQ-
LED control software.
During the first 500-600 working hours, we recommend performing a spectral calibration every 50 operating
hours.
After the first 500-600 operating hours, a calibration of every 150 working hours suffices.
Other factors that indicate the need for a spectral calibration include unsatisfactory illuminant generation, the
aberration of the intensity values, or a spectral curve that does not fit with the predefined standard illuminants of
the corresponding preset.
•
The spectrometer works correctly
•
The spectrometer settings are correct
•
All LED channels work correctly
•
The dark measurement is correct
•
Your measurement environment is correct
•
Your ambient temperature is correct
How to perform the spectral calibration is described in the iQ-LED control software manual.
4.4 Low-Intensity use
When using your system with very low intensity, the spectral measurement values will start to fluctuate. The
lower the intensity, the higher the fluctuation. The generated light is still stable up to a certain point. The
fluctuation of the values is caused by the noise of the spectral measurement of the internal spectrometer. The
higher the noise influence, the lower the light intensity. An approximate value will no longer be possible when
using standard illuminants with an intensity lower than 25 lux.
4.4.1 Low light in combination with a neutral density chart
You can use a neutral density filter chart and activate the neutral density correction in the iQ-LED control software.
The light source will run at a higher intensity while still having low intensity behind the chart plane. Please use the
'Density Filter Compensation' in your iQ-LED software to get the corresponding intensity behind the filter. Please
see chapter 3.1.3 in the software manual for details.
