Thus, the fundamental problem with using lux meters or luminance meters to measure plant illumination is that they underestimate blue (400–500 nm) and red (600–700 nm) light within the visible spectrum.
Humans perceive light within these ranges with reduced spectral sensitivity, but especially for plants, blue and red light are used extensively for photosynthesis. Therefore, the aforementioned photometric variables are unsuitable for assessing plant illumination.
The plant illumination spectrum can be measured and indicated using the MAVOSPEC BASE spectrometer from GOSSEN.
This instrument provides an initial indication of the extent to which the wavelength ranges necessary for plant growth are available.
MAVOSPEC BASE also determines the photosynthetic photon flux density (PPFD) (400-700 nm) across the entire spectral range, subdivided into the PPFD_blue (400-500 nm), PPFD_green (500-600 nm), and PPFD_red (600-700 nm) ranges, as well as the adjacent PPFD_UV (380-400 nm) and PPFD_FR (700-780 nm) ranges. This allows for the measurement and adjustment of the respective effects of plant lighting on growth, flowering, and aroma.
The measured values ​​can be recorded throughout the day using a computer and Excel spreadsheets.
MAVOSPEC BASE owners can download the firmware update free of charge from the GOSSEN website at www.gossen-photo.de. Complete information on plant lighting measurement can also be found there in the BLOG section.

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