Right now I’m working on a university project, which utilizes azolla or duckweed biomass production. For the automation process, we need some data to determinate the optimal harvesting moment. The Plants have different doubling times, for example one week, but after reaching a certain matt density they self inhibit their growth. For the Azolla plant this is reached after 2 kg/(m^2). So at this point the harvesting should be initiated.
My idea to determine this matt density was to measure the light reaching the bottom of the pond. For this i would install some LDRs inside a clear tube and collect the resistance over time. When the correct matt density is reached (measured by weighing the “pond”) I want to look at the data and hope, that there is a visible correlation.
In the attached PDF I have drawn the prototype.
Do you think a normal LDR (Gl5516)is viable and the 10 bit is enough?
Maybe you have a better idea for measuring a plant mat on a water surface.
Detecting the water level would also be quite helpful.
Thank you for your time!
Notiz 20.12.2018.pdf (1.72 MB)