Weather & Climate
Pressure and Weather
Due to the gravity earth is surrounded by a mantle of air (atmosphere). The static pressure that acts to the surface of the earth is called atmospheric pressure. Because of variable warming of the different latitudes, formation of the continents and seas and motion processes in the atmosphere the atmospheric pressure is uneven. The global mean value of the atmospheric pressure at sea level is 1013.25 hPa. In Central Europe it varies mainly between 990 and 1040 hPa.
The atmospheric pressure is closely linked with the weather situation, because first of all change in atmospheric pressure has determining influence to the formation of the weather. A slow but steady rise in atmospheric pressure gives outlook to a profound and settled improvement of weather whilst a sharp rise is often followed by a sharp fall and so changeable weather will be the forecast. The beginning fall in general indicates a worsening of the weather.
To measure the atmospheric pressure aneroid barometers use the distortion of flat, evacuated metal bellows. These bellows will be squeezed with rising pressure or expands with falling pressure. With the help of a precision mechanism this movement, which is only a few hundredths of a millimeter, is amplified and passed on to the pointer for indication.
Humidity of air and air temperature
The right temperature and optimum humidity mainly ensure comfortable and healthy living and working conditions. Depending of the use of rooms the room temperature is optimum between 18 and 22 ° C. For human beings the most healthy range of humidity in rooms is between 35-65%.
Optimum living and working conditions at minimal use of heating energy can mainly be achieved by active ventilation. You save heating costs by opening the windows short, but wide several times a day. This replaces the used and moist air very quickly with cold, but always dry and fresh air especially in cold weather conditions.
The advice of Stiftung Warentest (issue 03/2003): »Hygrometer can help to create good living environment at home. In homes with risk of high humidity, they are almost a must to prevent mold or to fight against.«
Especially useful for measurements of humidity in production and storage rooms, living rooms and offices are hygrometers with synthetic fibres. For more information please visit www.wohnklima-hygrometer.de.