Dew Point Calculator

Dew Point Equation:

\[ T_{dp} = \frac{243.5 \times \ln(e / 611.2)}{17.67 - \ln(e / 611.2)} \]

Dew Point Temperature (T_dp):

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1. What is Dew Point?

The dew point is the temperature at which air becomes saturated with water vapor, causing dew to form. It's a measure of atmospheric moisture and indicates how much the air must cool to reach saturation.

2. How Does the Calculator Work?

The calculator uses the dew point equation:

\[ T_{dp} = \frac{243.5 \times \ln(e / 611.2)}{17.67 - \ln(e / 611.2)} \]

Where:

\( T_{dp} \) — Dew point temperature (°C)
\( e \) — Water vapor pressure (Pa)
611.2 — Reference vapor pressure at 0°C (Pa)
243.5, 17.67 — Empirical constants

Explanation: The equation calculates the temperature at which water vapor in air condenses into liquid water.

3. Importance of Dew Point Calculation

Details: Dew point is crucial for weather forecasting, aviation, industrial processes, and comfort assessment in buildings.

4. Using the Calculator

Tips: Enter water vapor pressure in Pascals (Pa). The value must be greater than 0 for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between dew point and humidity?
A: While relative humidity depends on temperature, dew point is an absolute measure of moisture in the air.

Q2: What does a high dew point indicate?
A: High dew points (>18°C) indicate muggy conditions, while very high (>24°C) feels oppressive.

Q3: How is water vapor pressure measured?
A: It can be measured directly with hygrometers or calculated from other humidity measurements.

Q4: What's the relationship between dew point and frost point?
A: Frost point is the dew point when below freezing - the temperature at which frost forms.

Q5: Why is dew point important in aviation?
A: It helps predict fog, icing conditions, and potential aircraft performance issues.