Actual Vapor Pressure Calculator

Actual Vapor Pressure Formula:

\[ e = \frac{RH}{100} \times e_s \]

Actual Vapor Pressure (Pa):

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1. What is an Actual Vapor Pressure Calculator?

Definition: This calculator computes the actual vapor pressure based on relative humidity and saturation vapor pressure.

Purpose: It helps meteorologists, engineers, and scientists determine the partial pressure of water vapor in the air.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ e = \frac{RH}{100} \times e_s \]

Where:

\( e \) — Actual vapor pressure (Pa)
\( RH \) — Relative humidity (%)
\( e_s \) — Saturation vapor pressure (Pa)

Explanation: The relative humidity (as percentage) is divided by 100 to get a decimal value, then multiplied by the saturation vapor pressure to obtain the actual vapor pressure.

3. Importance of Actual Vapor Pressure Calculation

Details: Actual vapor pressure is crucial for understanding atmospheric moisture content, calculating dew point, and predicting weather patterns.

4. Using the Calculator

Tips: Enter the relative humidity (0-100%) and saturation vapor pressure (must be > 0). The calculator will compute the actual vapor pressure in Pascals.

5. Frequently Asked Questions (FAQ)

Q1: What is saturation vapor pressure?
A: The maximum vapor pressure that can exist at a given temperature when the air is saturated with water vapor.

Q2: Why is actual vapor pressure important?
A: It's used in weather forecasting, HVAC design, and understanding human comfort levels.

Q3: What units should I use?
A: Typically Pascals (Pa) for vapor pressure, but the calculator will work with any consistent units.

Q4: How do I find saturation vapor pressure?
A: It can be calculated from temperature using the August-Roche-Magnus formula or other thermodynamic equations.

Q5: What's the relationship between RH and vapor pressure?
A: RH is the ratio of actual vapor pressure to saturation vapor pressure, expressed as a percentage.