Vapor Pressure Of Water Calculator Mmhg

Magnus Formula:

\[ e_s = 6.112 \times \exp\left(\frac{17.67 \times T}{T + 243.5}\right) \times \left(\frac{760}{1013.25}\right) \]

Vapor Pressure (e_s):

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1. What is the Magnus Formula?

The Magnus formula is an empirical relationship that calculates the vapor pressure of water over liquid water. It provides an accurate estimation of saturation vapor pressure based on temperature, adjusted for mmHg units.

2. How Does the Calculator Work?

The calculator uses the Magnus formula:

\[ e_s = 6.112 \times \exp\left(\frac{17.67 \times T}{T + 243.5}\right) \times \left(\frac{760}{1013.25}\right) \]

Where:

\( e_s \) — Vapor pressure of water (mmHg)
\( T \) — Temperature (°C)
\( \exp \) — Exponential function

Explanation: The formula calculates the saturation vapor pressure by considering the exponential relationship between temperature and vapor pressure, with adjustment factors for unit conversion.

3. Importance of Vapor Pressure Calculation

Details: Accurate vapor pressure calculation is crucial for meteorological studies, humidity measurements, HVAC system design, and various industrial processes involving water vapor.

4. Using the Calculator

Tips: Enter temperature in degrees Celsius. The calculator accepts values within a reasonable range (-100°C to 100°C) for accurate results.

5. Frequently Asked Questions (FAQ)

Q1: Why use the Magnus formula instead of other vapor pressure equations?
A: The Magnus formula provides a good balance between accuracy and computational simplicity, making it widely used in meteorological and engineering applications.

Q2: What is the typical range of vapor pressure values?
A: Vapor pressure ranges from nearly 0 mmHg at very low temperatures to about 760 mmHg at 100°C (boiling point at sea level).

Q3: How does vapor pressure relate to humidity?
A: Relative humidity is the ratio of actual vapor pressure to saturation vapor pressure at the same temperature, expressed as a percentage.

Q4: Are there limitations to the Magnus formula?
A: The formula is most accurate for temperatures between -45°C and 60°C. Outside this range, other more complex equations may provide better accuracy.

Q5: Why is the unit conversion factor (760/1013.25) included?
A: This factor converts from millibars (commonly used in meteorological contexts) to mmHg, making the result more familiar for certain applications.