What is the concept of "relative humidity" often heard or seen in weather forecast?

The absolute humidity of air at a certain temperature is the percentage of water vapor saturation pressure in water at the same temperature, which is called the relative humidity of air at that time.

If p represents the absolute humidity of air at a certain temperature, p represents the saturated pressure of water vapor at the same temperature, and b represents the relative humidity, then

The water vapor saturation pressure of water at a certain temperature can be found from the table below. Therefore, knowing the absolute humidity, we can calculate the relative humidity; Conversely, knowing the relative humidity can also calculate the absolute humidity.

If the absolute humidity of air is p=800Pa, when the temperature is 20℃, the relative humidity of air is

When the temperature is 65438 00℃ C, the relative humidity of the air.

In a living room, the suitable relative humidity is about 60%, and the most suitable relative humidity for heading and flowering of rice is 70% ~ 80%.