Question

explain the difference between absolute humidity and relative humidity.what are their units.

Answer 1

$\bold{Absolute \: Humidity}$ is the measure of water vapor (moisture) in the air, regardless of temperature. It is expressed as grams of moisture per cubic meter of air (g/m3).

The maximum absolute humidity of warm air at 30°C/86°F is approximately 30g of water vapor - 30g/m3. The maximum absolute humidity of cold air at 0°C/32°F is approximately 5g of water vapor - 5g/m3.

$\bold{Relative \: Humidity}$ also measures water vapor but RELATIVE to the temperature of the air. It is expressed as the amount of water vapor in the air as a percentage of the total amount that could be held at its current temperature.

Warm air can hold far more moisture than cold air meaning that the relative humidity of cold air would be far higher than warm air if their absolute humidity levels were equal.