Feature Requests - Vapor pressure sensor

[Torgrima]

This is a very important sensor value, when growing plants.

WPD of the leaves tell you about the resperation of the plant.

VPD = VPleaf - VPair
VPleaf = 610.7 * 107.5Tleaf/(237.3+Tleaf) / 1000
VPair = 610.7 * 107.5Tair/(237.3+Tair)/1000 * RH/100

VPleaf - vapor pressure of the leaf (canopy) in kPa
VPair - vapor pressure of the air in kPa
Tleaf - leaf temperature in Celsius
Tair - air temperature in Celsius
RH - air relative humidity
VPD - vapor pressure deficit in kPa

Or simply, use the a chart VPD chart and calculator.
You need a thermometer/hygrometer to measure the grow room temperature, RH and ideally an infrared thermometer, so you can measure the canopy temperature. If you don't have an infrared thermometer, position your thermometer's remote probe at canopy level and take the reading after a few minutes, or assume that leaf temperature is 2°C cooler than air temperature.

In depth PDF article:
https://journals.ametsoc.org/downloadpdf/journals/apme/6/1/1520-0450_1967_006_0203_otcosv_2_0_co_2.xml

[4rianton]

+1 to this.. It would be great to allow the user to set the parameters of calculating VPD for a specific plant while configuring the integration.