martes, 2 de abril de 2013

About the WEATHER


THE WEATHER

A thermometer is a device that measures temperature or temperature gradient using a variety of different principles.



A barometer is a scientific instrument used in meteorology to measure atmospheric pressure.







A hygrometer is an instrument used to measure relative humidity. Relative humidity is a measure of how much water the air is holding, relative to the maximum amount of water the air could possibly hold at a given temperature.



Wind velocity or speed is measured by a cup anemometer, an instrument with three or four small hollow metal hemispheres set so that they catch the wind and revolve about a vertical rod. An electrical device records the revolutions of the cups and calculates the wind velocity.


A pluviometer is an instrument that is used to measure the amount of precipitation in the form of rainfall that has fallen at a given location over a specified period of time.