Photobiological Spectrum & DLI Model #53 & Transpiration Cycle Calculator
Calculate Daily Light Integral (DLI mol/m²/day), Vapor Pressure Deficit (VPD kPa), and transpiration watering intervals for Photobiological Spectrum & DLI Model #53.
Real-Time Field Reticle Verification
Need to verify this specimen in the field? Launch our browser camera to automatically track contours and confirm identity with confidence telemetry.
Open Live Camera →Operating Protocol & Usage Instructions
- Enter PAR light intensity (PPFD) measured at canopy level in μmol/m²/s.
- Specify daily illumination hours to calculate total delivered photons (DLI).
- Input ambient temperature and humidity to determine transpirational vapor deficit (VPD) and soil dry-down rate.
Scientific & Clinical Inquiries (FAQ)
What is Daily Light Integral (DLI)?
DLI measures the cumulative number of photons delivered to a square meter of foliage per day (mol/m²/day), calculated as PPFD × photoperiod × 0.0036.
Why is Vapor Pressure Deficit (VPD) superior to relative humidity alone?
VPD measures the drying power of air based on temperature differences between leaf surfaces and surrounding atmosphere, directly regulating stomatal opening and calcium transport.
What DLI is required to prevent stretching (etiolation)?
High-light plants like succulents require ≥15-20 mol/m²/day, whereas moderate tropical foliage thrives between 8-14 mol/m²/day.