VPD Calculator
Compute the leaf level vapour pressure deficit in kilopascals as saturation vapour pressure minus actual vapour pressure.
Description
Compute the leaf level vapour pressure deficit in kilopascals as saturation vapour pressure minus actual vapour pressure.
VPD Calculator is a focused biology tool that compute the leaf level vapour pressure deficit in kilopascals as saturation vapour pressure minus actual vapour pressure. It calculates locally from the values you enter and exposes the result without changing the source observations.1
When to use VPD Calculator
Use VPD Calculator when you need to compute the leaf level vapour pressure deficit in kilopascals as saturation vapour pressure minus actual vapour pressure. Enter Saturation vapour pressure and Actual vapour pressure using the definitions and units below so the result can be reproduced.
- Saturation vapour pressure
- A finite measured or assumed value, expressed in kPa.
- Actual vapour pressure
- A finite measured or assumed value, expressed in kPa.
How VPD Calculator calculates the result
The published tool contract uses this rule: Compute the leaf level vapour pressure deficit in kilopascals as saturation vapour pressure minus actual vapour pressure.1
- Vapour pressure deficit
- The calculated vapour pressure deficit in kPa.
Limitations of VPD Calculator
A ratio or percentage can conceal the scale of its numerator and denominator and becomes sensitive to measurement error when the denominator is small.
Alternative or Complementary measurements
Retain the original Saturation vapour pressure and Actual vapour pressure values and their units alongside the result. Leaf VPD From RH is useful when you instead need to compute the leaf vapour pressure deficit in kilopascals from leaf temperature using the Tetens equation for saturation vapour pressure, 0.6108 times e^(17.27 times temperature divided by temperature plus 237.3), scaled by one minus relative humidity over one hundred. Pressure Potential provides another view by helping you compute the pressure (turgor) potential in megapascals as the total water potential minus the osmotic potential; both inputs are signed.
References
-
Vapour-pressure deficit — Wikipedia contributors
Similar or alternative tools
- Leaf VPD From RH
Compute the leaf vapour pressure deficit in kilopascals from leaf temperature using the Tetens equation for saturation vapour pressure, 0.6108 times e^(17.27 times temperature divided by temperature plus 237.3), scaled by one minus relative humidity over one hundred.
- Pressure Potential
Compute the pressure (turgor) potential in megapascals as the total water potential minus the osmotic potential; both inputs are signed.
- Turgor Pressure Estimate
Estimate turgor pressure in megapascals as the total water potential minus the osmotic potential, floored at zero when the cell is flaccid; both potentials are signed and finite.