Weather forecasting has challenged the human mind from the earliest times, with much ancient worldly wisdom identified with weather lore and weather almanacs. Little progress was made in scientific forecasting, however, until the 19th century, when developments in the fields of thermodynamics and hydrodynamics provided the theoretical basis for meteorology. Exact measurements of the atmosphere are also of the greatest importance in meteorology, and the advance of the science has been furthered by the invention of suitable instruments for weather
station equipment, such as barographs thermographs, and by the organization of networks of observation stations to gather weather data. Weather records for individual localities were made as early as the 14th century, but not until the 17th century were any systematic observations made over extended areas.
Observations made at ground level
with the help of weather station
equipment are more numerous than those made at upper levels. They include the measurement of air pressure, temperature, humidity, wind direction and speed, the amount and height of clouds, visibility, and precipitation (the amount of rain or snow that has fallen). For the measurement of air pressure, the mercury barometer is the accepted standard. Aneroid barometers are also useful, particularly on ships and when used in the recording form called a barographs thermographs to show the trend of pressure change over a period of time. All barometric readings used in meteorological work are corrected for variations resulting from temperature and the height of the station, so that pressures from different stations may be directly compared.
For the observation of temperature many different types of thermometers are employed. For most purposes an ordinary thermometer covering an appropriate range is satisfactory. It is important to place the thermometer as weather
station equipment in such a way as to minimize the effects of sunshine during the day and of heat loss by radiation at night, thus yielding values of the air temperature representative of the general area.
According to the definition, thermograph is a recording thermometer, used with a special pen which is recording temperature on a circulatory cylinder. This pen is controlled by so-called bi-metal strip which is bending when temperature changes. Speaking about another kind of weather station equipment we should pay attention to barographs - the devices producing a paper called barogram with all the changes of barometric pressure. One or even more aneroid cells are used in barographs
Barographs thermographs are the most widespread. Atmospheric pressure is caused by the weight of air. That`s why it`s necessary to use barographs thermographs for this factor`s assessment. They are widely used in short-term local forecasting. As a rule, they operate on an aneroid principle. Some barographs which have displays offering extra features, that make them pretty attractive. Most of the barographs thermographs usually have mechanical eight-day clocks with a seven-day chart, showing the rotation of the drum. These charts are available in millibars or inches of mercury. The start of the week can be either Monday or Sunday. There exist several well-known barographs thermographs producers, such as Wescor Inc., Enviro Technology Service, Stevens Water Monitoring Systems, NovaLynx Corporation, Ben Meadows Company and others. For example, NovaLynx Corporation is pretty well-known for carrying a complete line of weather instruments including snow and rain gauges, wind vanes, anemometers, evaporation sensors and pans, electronic sensor technologies. Thus, the majority of them offer the customers high-quality environmental equipment and products for outdoor professional, everything necessary for water, soil and atmospheric testing.