Difference between Humidity and Relative Humidity.
📌 Difference between Humidity and Relative Humidity
1. Humidity
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Definition: The amount of water vapor present in the air at a given time.
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Measurement: Usually expressed in grams of water vapor per cubic meter of air (g/m³).
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Type: Known as Absolute Humidity.
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Limitation: Does not account for temperature — it only tells how much water vapor is present, not how close the air is to being saturated.
2. Relative Humidity (RH)
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Definition: The ratio of the actual amount of water vapor present in the air to the maximum amount the air can hold at that temperature, expressed as a percentage.
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Formula:
RH(%)=Actual Vapor PressureSaturation Vapor Pressure at that Temperature×100RH (\%) = \frac{\text{Actual Vapor Pressure}}{\text{Saturation Vapor Pressure at that Temperature}} \times 100
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Example:
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If RH = 50%, the air holds half the moisture it could hold at that temperature.
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At RH = 100%, the air is fully saturated → condensation/rainfall occurs.
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Application: More practical in pharma cleanrooms, warehouses, and stability chambers where both moisture and temperature matter.
✅ Key Difference in One Line
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Humidity = actual water vapor content (absolute measure).
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Relative Humidity = water vapor content relative to maximum capacity at a given temperature (percentage).