what is the dewpoint?

Answer 1

the temperature that water vapor in the air condenses into a liquid (dew).

Answer 2

When you speak of dew point, you are referring generally to any liquid and vapor system. In the case of the weather, the liquid vapor system is water and air. On a normal dry day, you can have water vapor in the air, but at a level that is not noticeable to eye or body. An example would be a warm day on a lake.

Now for any given temperature there is a maximum concentration of water that can exist in air. If you are just below 100 percent of that concentration, it feel very humid, but there will be no rain. Now drop the temperature 1 degree, and you have exceeded the maximum water concentration in the vapor phase, and you will get rain.

Another way to demonstrate the dewpoint is to take of glass of water at room temperature and add several ice cubes. As the contents of the glass begin to cool, the outside of the glass will cool also, and soon water will appear on the glass. At precisely the point where water first condenses on the glass, you will be at the dewpoint.

The more water vapor in the air, the closer you are to the dewpoint and the more humid it feels. When the weather man talks of humidity, they generally refer to "relative humidity with a number between zero and 100 percent. What that means is that say for example, we have 70 percent humidity, the air then contains 70 percent of the maximum water that it can for the given temperature.

Answer 3

Vapor of liquid substances is always present above the surface of the liquid itself. Depending on the amount of the liquid, more or less vapour can be found in the environment.

The vaporisation of the liquid dependes on the environmental temperature and pressure. Higher the temperature, more the liquid is vaporized. higher the pressure, less liquid is vaporized.

The dewpoint is the value of the temperature at the specified pressure, at which the vapour condenses into the liquid phase. It changes, due to the pressure variations.

The most important dewpoint is the one for the water vapour. It has been analysed for a long time, and many tables for it's determinations were made. So, when You need the specific dewpoint for water at a specific pressure of temperature, You should refer to those tables. There is also a calculation for it, but it requires menitioned tables, so it is much easier to use the tables themselves.

Answer 4

a dewpoint is the temperature at which water vapor in air condenses into liquid at constant pressure. Example at 7 degree celcius and atmospheric pressure (14.7 psi)
water vapor condenses as shown in outer surface of glass containing very cold water. The dewpoint in this example is 7 degree celcius.

Answer 5

The dew point or dewpoint of a given parcel of air is the temperature to which the parcel must be cooled, at constant barometric pressure, for the water vapor component to condense into water, called dew. When the dew point temperature falls below freezing it is called the frost point, instead creating frost or hoarfrost by deposit

Answer 6

The dewpoint, the quantity meteorologists actually measure to determine the humidity. Meteorologists on the Weather Channel and local TV stations are using the dewpoint more and more in their reports and forecasts.

Answer 7

Dew point is a property of vapour mixtures.
It depends upon pressure and composition.
It is the temperature at which the first liquid droplet is formed.
It's not necessarily water in air. It could be, for example, a ethanol-water mixture.
For example, some Natural Gas Processing Plants are called D.P.P. (Dew Point Plant), cause they just remove the heavy components of the natural gas by passing it through a valve (isenthalpic process).
O hope I have helped you.

Answer 8

The dew point temperature is the temperature to which the air must be cooled to reach saturation (assuming air pressure remains the same). The dew point is a direct measure of the amount of moisture present in the air, and directly affects how you feel... or in other words... measures the amount of humidity in the air. Remember, the temperature never drops below its dew point, but can drop to it. Generally, we start to feel some discomfort when the dew point gets to or just above 60 degrees. ...

Answer 9

The temperature at a certain pressure that water comes out of it's vapour state and starts to condense into droplets.

The temperature that a cloud needs to be at to start raining.

Answer 10

Forming of water droplets by falling of temperature - below to average of condensing atmosphere