Summary of "[중③ 2단원] 4-2강. 포화 수증기량 곡선 해석하기! 👉🏻 포화 수증기량┃상대 습도┃이슬점┃응결량 쉽게 찾아내는 방법✍🏻"

Scientific concepts and phenomena

Saturated water-vapor content The maximum mass of water vapor air can hold at a given temperature (read from the saturation curve). Units: g/m³.
Actual water-vapor content The current mass of water vapor present in the air (g/m³).
Relative humidity (RH) The ratio of actual water-vapor content to the saturated water-vapor content at that temperature, usually expressed as a percentage.
Dew point The temperature to which air must be cooled (at constant water-vapor content) to reach saturation; below that temperature condensation (dew) begins.
Condensed (condensation) amount The mass of water that condenses when air is cooled from its current temperature to a lower temperature — the difference between the current actual vapor and the saturation vapor at the lower temperature.

To get saturated water‑vapor content at a given temperature
- Move vertically from the given temperature until you hit the saturated‑vapor curve; read the corresponding vapor amount (g/m³) on the vapor axis.
To get actual water‑vapor content
- From the air’s current state point, read the vapor amount on the vertical (vapor) axis (g/m³).
To compute relative humidity
- Use: RH = (actual water‑vapor content / saturated water‑vapor content at that temperature) × 100%
To find the dew point
- From the current actual vapor content, move left (decrease temperature) until you intersect the saturated‑vapor curve; the temperature at that intersection is the dew point.
To find the amount of condensation when cooling to a new (lower) temperature
- Condensed amount = current actual water‑vapor content − saturated water‑vapor content at the target (lower) temperature

Saturated vapor at current temperature ≈ 27.2 g/m³ (video also states 27.1 g/m³).
Actual water‑vapor content = 14.7 g/m³.
Relative humidity ≈ 14.7 / 27.2 ≈ 0.540 → ≈ 54%.
Dew point (for air A) = 20 °C (temperature at which 14.7 g/m³ intersects the saturation curve).
If cooled to 0 °C, saturated vapor at 0 °C ≈ 3.8 g/m³ → condensed amount = 14.7 − 3.8 = 10.9 g (of water per unit air volume, as used in the graph).