The ordinary thermodynamic temperature of the air, what you would measure with a regular thermometer. This is in contrast to the wet bulb temperature, which is the temperature reached by a wet surface. A classical weather station uses a sling hygrometer to measure the two. This is a pair of thermometers, one of which has a wet covering, something like a sock that can be dipped in water. By measuring both of these the humidity can be determined. Temperature of the free air as measured with a dry thermometer on a sling psychrometer over a grassy surface at a height of approximately 6 feet (1.8 meters).
-9c
for air water system wet bulb equals to dry bulb at 100 % relative humidity for that given temperature of air.
A wet bulb measures the temperature after water evaporation allows to cool and a dry bulb measures air temperature.
the "current" temperature, ie, the temperature at which wet bulb and dry bulb are the same. when the wet bulb and dry bulb temperaturs equalized the dew point emperature equals them, because the air is saturated now.
it is difference between wet bulb temperature and dry bulb temperature.
Dry bulb Temperature - Dew Point Temperature
the evaporation off the moisture on the wet bulb absorbs the heat.
The wet and dry bulb thermometers are used in conjunction with each other to determine relative humidity. The Dry Bulb temperature (by itself) measures ambient air temperature. The "Dry Bulb" identification indicates that this temperture is not affected by humidity. The Dry Bulb Temperature refers basically to the ambient air temperature. It is called "Dry Bulb" because the air temperature indicated by a thermometer not affected by the moisture content (humidity) of the air. The Wet Bulb temperature is trchnically called "the temperature of adiabatic saturation" It is measured by a thermometer with its bulb wrapped in moist cloth or cotton fiber. Aair passing over the wet bulb evaporates the water from the cloth and cools the bulb. The temperature difference between the dry bulb and wet bulb depends on the humidity of the air. The two tempertures can be placed on a Psychometric diagram (also called a Mollier chart) to determine relative humidity at the dry bulb temperature.
Because the process of evaporation absorbs heat from the bulb.
The dry-bulb temperature is the temperature of air measured by a thermometer freely exposed to the air but shielded from radiation and moisture. Dry bulb temperature is the temperature that we usually think of as air temperature. It is the temperature measured by a regular thermometer exposed to the airstream. Unlike wet bulb temperature, dry bulb temperature does not indicate the amount of moisture in the air. In construction, it is an important consideration when designing a building for a certain climate. Nall called it one of "the most important climate variables for human comfort and building energy efficiency."http://en.wikipedia.org/wiki/Dry-bulb_temperature
You use a Hygrometer.
difference between dry bulb temperature and wet bulb temperature which is usually different from each other...like WBT is always less than DBT!! But at 100% relative humidity both are same!!..