Do Try This at Home!!

Make Your Own Weather Instruments

I have provided information on the following weather instruments:

Anemometer, Barometer, Hygrometger, Rain Guage, Thermometer, Wind Vane, (Easy)

 

In order for meteorologists to accurately forecast the weather, they need to measure various atmospheric conditions, such as air pressure, humidity, precipitation, temperature, wind speed, and wind direction. Meteorologists use special instruments to collect data on weather conditions.

A weather forecast is a prediction of weather conditions over the next three to five days. Meteorologists observe and collect data on current weather conditions in order to provide reliable predictions for future weather.

In this activity, you will make a a variety of weather instruments.


Anemometer
Measuring wind speed can be done with minimal equipment and surprising accuracy.
PURPOSE:
To determine the speed or velocity of the wind.
MATERIALS:
1. strong thread or thin fishing line (about 40 cm long).
2. ping -pong ball.
3. large protractor.
4. glue and tape.
5. thick cardboard (for mounting protractor).
DIRECTIONS:
1. Copy the string angle/wind speed conversion chart (seen below) on the card board.
2. Mount the protractor with tape to the cardboard, curved side pointing down.
3. Tape or glue the thread to the ping-pong ball.
4. Tie or glue the other end of the thread to the center of the protractor.
5. When the wind blows the thread off center, read the angle on the protractor.
6. Convert this angle to the wind velocity in the conversion chart.
7. Use your instrument outside and away from buildings to measure wind speed. At the same time, use the Beaufort Wind scale to write down your observations about the strength of the wind.

String angle - 90 - 80 - 70 - 60 - 50 - 40 - 30 - 20
(degrees)
Speed (mph) - 0-- --8-- 12- 15- -18- -21- -25- -32

Go Beyond:
Evaluate the accuaracy of your anemometer by comparing your results with the schools (real time) weather station wind speed.
Can you suggest any improvements to the instrument?


Barometer
Air has weight. It exerts pressure on us and on everything aroud us. As aire pressure rises, it forces the balloon down into the jar, making the end of the straw rise.
PURPOSE:
To measure a rise or a drop in the atmospheric pressure.
MATERIALS:
1. jar
2. large piece of balloon rubber
3. strong rubber band (to fit around the jar)
4. short drinking straw
5. adhesive tape
6. cardboard and paper
DIRECTIONS:
1. Stretch the balloon rubber over the jar and secure it with a strong rubber band.
2. Tape the pin to the end of the straw and glue it to the centre of the balloon.
3. Support the cardboard upright and write your scale on the paper.
4. Look at the scale of the barometer the same time each day. Note where the pin is pointing compared to the day before. If the pin is lower on the scale, it means the atmospheric pressure is increasing. If the pin is higher, pressure is decreasing.
5. If the pin is lower on the scale, it means the atmospheric pressure is increasing. If the pin is higher, pressure is decreasing.
6. Record your results daily (whether the air pressure is falling, rising or steady).

 

Go Beyond:
Evaluate the accuaracy of your air barometer by comparing your results with the recording barometer found in the classroom (K-5)
Can you suggest any improvements to the instrument?

Thermometer
This thermometer demonstrates the way in which substances expand and contract when heated and cooled.
PURPOSE:
To determine the increase or decrease of air temperature.
MATERIALS:
1. bottle
2. straw
3. plain cardboard
4. small piece of clay (used chewing gum will work!).
5. two bowls half-filled with water
6. cup of dyed water, containing a little cooking oil
DIRECTIONS:
1. Stand a thin straw in a cup containing dyed water. Tightly place your finger over the top end of the straw.
2. Lift the straw out, ensuring that some dyed water is trapped within the straw. Place the straw into the empty bottle. Put the clay around the top of the bottle and straw.(Assistance may be needed.) The dye should be suspended in the straw even when you lift your finger off.
3. Carefully attach the cardboard to the straw with sticky tape.
4. Fill a bowl with warm water and another with iced water.
5. Place the bottle and straw into the bowl of warm water. Wait for five minutes and then carefully mark on the cardboard the height reached by the dye.
6. Now put the bottle into the bowl which has water and ice in it. After five minutes, mark on the cardboard the height of the dye.

Go Beyond:
Evaluate the accuaracy of your thermometer by comparing your results with a "real" thermometer. (Using the "real" thermometer, draw on a new piece of cardboard the temperature scale.)
Can you suggest any improvements to the instrument?

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Wind Vane
Measuring wind speed can be done with minimal equipment and surprising accuracy.
PURPOSE:
To determine which direction the wind is blowing.
MATERIALS:
1. thin wooden dowel or a straw (about 30 cm long)
2. a small piece of stiff card or masonite (6cm X 6 cm)
3. a block of wood for mounting
4. nails
5. glue
6. a small bead
DIRECTIONS:
1. Cut your card or masonite along the diagonals to make two triangles. These will be the arrows on each end of the weather vane.
2. Attach these triangles to the dowel or straw with glue or nails.
3. Balance the dowel or straw to find the exact center. Mark this spot.
4. Drill a very small hole or make a hole with a pin at this spot.
5. Use a nail or pin to mount your dowel or straw on top of your block of wood allowing it to rotate on a small bead.
6. Write on the wood or add labels to show the directions - N,S,W,E
7. Using a compass, line up the labels to the correct directions.
8. Observe which direction the arrow points into the wind. Record your observations.

Go Beyond:
Can you suggest any improvements to the instrument?

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Make an Easy Wind Vane
Measuring wind direction can be done easily with minimal equipment.
PURPOSE:
To determine which direction the wind is blowing.
MATERIALS:
1. 1 straw
2. 1 straight pin
3. index card
4. pencil with eraser
5. tape
DIRECTIONS:
1. Cut the point and tail of an arrow out of an index card.
2. Tape them onto the ends of the straw.
3. Push the pin through the middle of the straw.
4. Stick the pin into the eraser of the pencil. Make sure the straw can turn freely.

Go Beyond:
Can you suggest any improvements to the instrument?

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Hygrometer
The human hair cells will indicate the level of moisture in the air by expanding and contracting. When their air is moist, the hair will expand and lengthen, making the pointer point down. When the air is dry, the hair will contract and shorten, making the pointer point up.
PURPOSE:
To determine the increase or decrease of moisture in the air.
MATERIALS:
1. a scrap piece of wood or flat styrofoam (about 9 inches long and 4 inches wide)
2. a flat piece of plastic (about 3 inches long and 3 inches wide) thin enough that you can cut
3. 2 small nails
4. 3 long strands of human hair (about 8 inches long)
5. a dime
6. glue, tape, hammer, and scissors (strong enough to cut plastic)
DIRECTIONS:
1. Cut the piece of plastic into a triangular shape (refer to pictures).
2. Tape the dime onto the plastic, near the point.
3. Poke one of the nails through the plastic pointer, near the base of the triangle.
4. Wiggle the nail until the pointer moves freely and loosely around the nail.
5. On the plastic pointer, between the dime and the nail hole, glue the hair strands to the plastic.
6. Position the pointer on the wood or styrofoam base about three quarters of the way down the side. (Refer to picture.)
7. Attach the nail to the base. The pointer must be able to turn easily around the nail.
8. Attach the other nail to the base about one inch from the top of the base, in line with the pointer.
9. Pull the hair strands straight and tight so that the pointer points parallel to the ground. That is, make sure the point of the pointer is perpendicular to the hair. The hair should hang perfectly vertical and the pointer should point perfectly horizontal.
10. Glue the ends of the hair to the nail. If the hair is too long, trim the ends.
11. When you make your hygrometer observations each day, you should make a mark to indicate where the pointer points. Over time, you'll be able to see the humidity patterns that will help you forecast the weather.

Go Beyond:
Evaluate the accuaracy of your hygrometer by comparing your results with the hymidity trend on the Lindero Canyon Weather Station.
Can you suggest any improvements to the instrument?

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Rain Guage
A rain guage measures the amount of precipitation.
PURPOSE:
To determine the amount of rainfall.
MATERIALS:
1. clean liter soda bottle (without the cap or label tape)
2. 2 different color markers
3. scissors
4. ruler
DIRECTIONS:
1. Cut off the top of the soda bottle (about 3 1/2 - 4 inches down from the top of the bottle).
2. Insert the top of the bottle that was cut off into the bottom of the bottle.  It should look like a funnel.
3. Tape the two parts of the bottle together.
4. Place the ruler next to the container so that the 1 inch marker is near the bottom of the container.
5. Using one of the markers draw a line at each inch.
6. Using the other marker draw a line at each half inch.
7. Place your rain guage outside in the open (away from buildings and fences). Bury the bottom into the soil so that strong winds will not cause the rain guage to topple over. (You might hot glue the rain guage to a plate and anchor the plate in the soil.)

Go Beyond:
Bury the bottom into the soil so that strong winds will not cause the rain guage to topple over. (You might hot glue the rain guage to a plate and anchor the plate in the soil.)
Can you suggest any improvements to the instrument?

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Did You Know?
On weather maps, lines joining places which have the same air pressure are called isobars.

Air expands by about 7 per cent when it warms from 32° F to 72° F.

When humidity is very high, perspiration evaporates too slowly to cool the body. This is why days of high humidity can be most uncomfortable.

FAST FACTS Cloud particles consists of tiny droplets of liquid water or ice. The size of these particles ranges from approximately 0.005 to 0.075mm).

More tornados form in the United States than anywhere else on Earth.

 

Anemometer, Barometer, Hygrometger, Rain Guage, Thermometer, Wind Vane, (Easy)