What this work is about, in plain words
How can one calculate how much light energy a culture receives from LEDs? The authors gave a step-by-step algorithm using three LEDs as an example and warned that datasheet values cannot always be trusted.
LEDs are convenient for growing microalgae: they can be assembled into a source with the desired spectrum, they heat up little, and they use the least energy per unit of light. But light conditions in research are described in different units — watts, microeinsteins or lux — and lux is designed around the sensitivity of the human eye. This makes results hard to compare. The authors set out to give an algorithm for calculating the energy characteristics of LED radiation for photobioreactors.
The algorithm is shown using three ultra-bright LEDs as an example: from the manufacturer's datasheet values to the energy reaching the illuminated surface.
The authors warn that LED characteristics declared by manufacturers do not always match reality. So the spectrum and power of the source should be regularly checked by direct measurement. For the case where light is measured with a lux meter, a formula for converting illuminance into radiant energy is given.
The work is useful for those who design LED lighting for cultivators and want to describe light conditions comparably.
Limitations. This is a calculation method using 2009 LEDs as an example. The specific figures are outdated, but the approach itself remains applicable.