Inputs
6 parameters · live recalculation on every change
-10C
Optimal: 22 - 27C
50C
Nominal
0%
Target: 55 - 75%
100%
0.80 - 1.20 kPa
Profile: Aeroponic Root Chamber #04
ⓘ Basis of calculation How it’s computed
1
Measure air temperature, relative humidity, growth stage, altitude and leaf temperature offset.
2
Convert temperature into degrees Celsius if working in Fahrenheit.
3
Compute saturation vapour pressure of the air using the Tetens equation: SVP = 0.6108 · e^(17.27T / (T + 237.3)).
4
Compute leaf saturation vapour pressure using the leaf temperature (air temperature + leaf offset).
5
Compute actual vapour pressure: AVP = SVP(air) × RH / 100.
6
True leaf VPD = SVP(leaf) − AVP; apply the altitude pressure factor, then classify against the growth-stage target.
Live output
True Leaf VPD
0.75
kPa
True Leaf VPD
Below Target · reduce RH to lift VPD toward 0.8–1.2 kPa
Air VPD
1.11
kPa
Sat. Vapour Pressure (Air)
3.17
kPa
Sat. Vapour Pressure (Leaf)
2.81
kPa
Actual Vapour Pressure
2.06
kPa
Mode
standard
Active profile
0.75
kPa
0.4 spore risk
0.8–1.2 target
1.6+ closure