Often small droplets of water are seen on plant leaves in the morning during winters. The droplets are known as dew. The Dew Point Temperature is the temperature when the water vapour in the air starts condensing out of the air.
Why is this temperature is so important?
It is the lowest temperature at which the air becomes saturated with water vapour. Above the Dew Point, moisture stays in the air; it doesn’t condensate at normal conditions. Dew Point temperature indicates the level of humidity in the air. If the Dew Point is well below dry air temperature, relative humidity of the air should be low. At higher relative humidity, the Dew Point temperature becomes close to the dry air temperature.
Dew Point Temperature remains the same in an environment until more water vapour is not added to the environment or removed from it. Dew Point Temperature and Wet Bulb temperatures are related, dew point temperature cannot be higher than the wet bulb temperature. Both become equal when air has 100% relative humidity.
The dew point temperature is measured with the help of a hygrometer. This device has a polished mirror that cools down when air is passed over it. When dew forms on the mirror, the temperature is called the dew point temperature of the air.