Weather Station Instruments
Posted On: 2009-01-05
Simple Barometer -This device shows atmospheric pressure. Use a glass or clear plastic quart bottle. Fill it with water, put a saucer over the top, and turn it over quickly. Allow a little water to escape into the saucer. With a felt-tipped pen, draw 8 or 10 scale marks 1/8 inch apart. The middle mark should be even with the water level. Check it each day. If the water level has risen, the atmospheric pressure is higher and fair weather is coming. If the level is lower, look for unsettled weather.
Anemometers -These devices measure wind velocity. For the one on top, use a paper plate and paper cups with handles. Staple cups to plate's rim as shown. Drive small nail into end of stick and punch through center of plate so that the plate turns freely. If you paint a stripe on one of the cups, it will be easier to count the number of revolutions and thus estimate the wind's speed. The slingshot anemometer (two bottom most drawings) requires an adult's help to make. Cut parts from wood and tin as shown. To set the scale on the instrument, hold it outside a car window on a windless day. With the car going 5 miles per hour, mark the degree of the blade's swing on the scale. At 10mph, make another mark, and so on. If the blade swings to its top limit at low speeds, weight with sinkers and start over.
Wind and Weather Chart -Here's a good way to keep track of the wind's direction over a month's time. The legs of the chart show the wind direction by dates. The squares beside the dates are painted different colors to show weather conditions each day-yellow for sunny, blue for cold and dry, red for warm and dry, etc.