Learner
Outcomes - By completing these activities, the learner will:
Learner
Outcomes - By completing these activities, the learner will:
Part 2. Constructing a hygrometer - Learners construct a device for measuring humidity.
Part 3. Constructing an anemometer - Learners construct a device for measuring wind speed.
Part 4. Making observations - Learners make observations using measuring devices they have constructed in Parts 2, 3.
Activity 1 - Understanding Weather Phenomena
Activity 2 - Internet Weather Resources
Here is a list of Russian Internet weather servers:
You may also use a temperature part of the Super-Kids' on-line metric converter to convert Farenheit degrees into Celsius and back.
Activity 3- Satellite Information about Weather
You can also get information about the weather by looking at satellite images of Earth. Here are some images from NOAA satellites:
White parts of the images represent clouds. Looking at satellite images, you can track cloud movements above the Earth. To do so, use today's and yesterday's satellite images. On each of them, find the area where you live. Compare the images and try to decide in what direction the clouds are moving in your area. Try to predict where the clouds will be tomorrow. Write down your conclusions. The following day, perform the same analysis to check if your prediction was correct. Explain any differences between your prediction and the actual position of clouds.
Topics for discussion:
To collect weather data, you will need:
Part 2: Constructing a Hygrometer
In this activity you will construct a hygrometer - an instrument for measuring relative air humidity. Before construction, look at the scheme of the instrument below.
Step 1
Find the most important part of our future instrument – a hair. It should be straight and have the length of about 25-30 cm (10-12 inches). Human or horse hair becomes longer when air humidity increases.
Step 2
Prepare the hair for use in the device by removing any oils or other fats (it will more easily absorb and evaporate steam). In order to do that, put it into alcohol or petrol for a day, than wash in hot water.
Step 3
Make a frame for the instrument. You may use LEGO sets or other plastic plates. The frame should look like a letter Ï with a height of about 20 and a width of about 10 cm (8 in. and 4 in. respectively), with a horizontal plate at the height of about 5 cm (2 in.) above the base (position (a) on Figure 1).
Step 4
Put the frame on a stand (b), made from wood or any other material, and fix the frame in that pîsition. The way of fixing (by glue or by screws) depends on the material of which the frame and the stand are made.
Step 5
Make a hole in the middle of the upper horizontal bar or drive in a nail One end of the hair will be fixed there. You can use any way of fixing it.
Step 6
Cut a metal or plastic plate. It should weigh 10 g and will serve as a counterbalance (g).
Step 7
Make two holes in the plate with the diameter of about 0.1 mm (burn them through if the plate is plastic or punch them if the plate is metal). The holes should be located in the middle of the plate (by the width) and at a distance of about 0.1 and 0.4 of the length of the plate from the ends of the plate.
Step 8
From a wire, make an arrow (d) with a diameter of 1 mm and a length of 15 cm.
Step 9
Glue the arrow to the counterbalance plate at the right angle next to the hole located closer to the end of the plate.
Step 10
Fix the arrow and counterbalance plate on the lower horizontal bar of the frame. The following two conditions are important. First, fix them so that they can freely revolve around the fixing point, and second, fix them so that the second hole of the counterbalance plate is approximately on the vertical axis of the frame.
Step 11
To do that, use the hole in the counterbalance plate, near which you have fixed the arrow. If the frame is metal, you can drill a small hole in it and secure all details with a screw. If the frame is plastic, use a pin (if you heat up the pin until it is red, then it will easily penetrate plastic and stay there).
Step 12
From any material (paper, plastic, etc. ), cut a scale plate (e). It is shown on the picture as an ellipse, but you can choose any form. The material should be such that you can easily write on it.
Step 13
Fix the scale plate (e) on the frame of the instrument. The height must be enough for the arrow to cross the scale.
Step 14
Place the hair (ñ) into the instrument. Fix one end of the hair in the free hole of the counterbalance plate, the other end - in the hole that you made in the upper plate of the frame. Choose the length of the hair so that the arrow is positioned approximately vertically.
Step 15
On this step you will create a grid on the scale. First, put the instrument, together with a plate of water, under the glass cowl. Evaporating water will create 100% humidity, the hair will become longer and the arrow will go to the right.
Step 16
Remove the cowl. Mark the place where the arrow stopped and write "100%" next to the mark.
Step 17
Place the instrument in almost completely dry air. To do so, cover it with a cowl and put a cup of phosphoric anhydride or calcium chloride under the cowl (you might find them in the chemical laboratory in your school).
Step 18
Remove the cowl. Mark the place where the arrow stopped and write "0%" next to the mark.
Step 19
Divide the distance between 0% and 100% marks into 100 equal parts (you may use a ruler).
Step 20
Mark the scale according to the table
below (the upper row of figures represents the points of division, the
lower row - percentages of relative humidity).
| 0 | 5 | 10 | 15 | 20 | 25 | 30 | 35 | 40 | 45 | 50 | 55 | 60 | 65 | 70 | 75 | 80 | 85 | 90 | 95 | 100 | |
| 0 | 2 | 5 | 8 | 9 | 12 | 15 | 18 | 21 | 24 | 28 | 32 | 36 | 41 | 47 | 54 | 61 | 70 | 79 | 89 | 100 | % |
Step 21
If your school lab has a hygrometer, use it to make a scale on the hygrometer you have made. Take both devices and put them in different conditions (in the bath, sauna and so on). Read the data from the laboratory hydrometer and write it on your hygrometer's scale.
The hydrometer is now ready to use!
Part 3: Constructing an anemometer.
This device consists of four parts – a wire frame with a handle, a scale and two wind measuring plates. Before construction, look at the scheme of the instrument below.
Step 1
Cut the first plate (100 x 120 mm) from a thin tin or hard plastic. You'll need two plates of the same size, but different weight (16 and 64 g), so make them from different materials.
Step 2
Mark two points near the narrow (100 mm) side. The points should be 10 mm from the narrow side and 15 mm from each of the wide sides. These points will be centers of the two holes.
Step 3
Make two holes with à diameter of 4-5 mm at the marked places.
Step 4
Weigh the plate. It should weigh 16 g. If the plate weighs more, you'll use it as the 64 g plate, by putting additional weight on it. If the plate weighs less than 16 g, add more weight.
Step 5
Begin making a frame. It’s convenient to construct it from LEGO bricks but you can use other materials as well.
Take a wire with a diameter of about 5 mm (it should be hard enough to keep shape), make a frame in the form of a rectangle (105 x 125 mm). Connect the ends of the wire by a strant in the middle of a narrow side of the rectangle (later you'll fasten a handle there).
Step 6
Fasten (by glue or a thin wire) two wire hooks to the narrow side of the frame (see the picture). They should be attached symmetrically, the distance between them should be equal to the distance between the holes in the wind measuring plates.
Step 7
Check your work – the plate hung by the hooks should freely swing within the frame.
Step 8
Make a cylindrical handle for the instrument from wood or plastic. Choose the length of the cylinder so that it would be comfortable to hold the device in your hand, but it shouldn’t be too long, so that you can easily carry it from place to place.
Make a hole at one end, so that the strand can easily enter it. You can drill a hole or use a plastic tube for a handle.
Step 9
Fix the frame on the handle - for example, pour some glue into the hole in the handle, thån insert a wire strand into the hole and wait until the glue is dry.
Step 10
Cut the scale of your instrument from tin or plastic. It should be in the shape of a ring. The inner radius of the ring is 120 mm, an outer radius is 140-150 mm.
Step 11
Decide how to attach the scale to the handle of the frame. If the scale is made of plastic, it can be fixed by scotch tape, if it is made of tin, you can attach it by a screw and a screw-nut. Moreover, you can make a small cut in the handle, in its upper part, and glue the scale into it. There also exist other variants, depending on the materials you are working with.
Step 12
Before you secure the scale, you should mark it. You can see on the picture how to mark it (the first point corresponds to deviation of the plate from a vertical line by 4 degrees, the second point - 12 degrees, the third - 24 degrees, etc).
Step 13
Attach the marked scale to the handle perpendicular to the frame.
Step 14
Hang the plate by the hooks.
The instrument is ready!
To measure the speed of wind, take the instrument by the handle and turn the scale in the direction of the wind. In doing so, it’s better to raise it above your head, so you don't block the wind.
The stronger the wind, the more it
deflects the plate. The relationship between the speed of wind and the
scale is as follows:
| Light (16 g) plate | Heavy (64 g) plate | |||||||||
| The mark of the scale | 1
(40) |
2
(120) |
3
(240) |
4
(370) |
5
(510) |
1
(40) |
2
(120) |
3
(240) |
4
(370) |
5
(510) |
| The speed of wind | 1 | 2 | 3 | 4 | 5 | 2 | 4 | 6 | 8 | 10 |
Step 15
Begin observations with the light plate. If the wind is stronger than you expected, and the plate moves out of the marked scale, change the plate to a heavier one. Then continue your observations.
Step 1
Make observations in your home town and find the most and least windy, the wettest and the driest places. Try to understand the reasons of their peculiarities.
While making observations, try to measure not only the parameters that your instruments can measure, but also other parameters (temperature, pressure). It will give you more data for comparison with meteorological information.
Step 2
Compare the results of your observations with the data from a meteorological station or from the Internet. Do they agree? If not, how can you explain the differences?
Step 3
Send the results of your observations and your comments to your fellow students from another school.
Concept Applications and Extensions
Obviously, the existing network of meteorological stations is not dense enough to register even significant changes in weather and climate. For example, the shallowing of Caspian Sea that continued for 50 years and then changed to the reverse process, does not match existing meteorological data. It is clearly more difficult to track precipitation and evaporating above the aquatoria than on the land. But even on the land we come across such problems every now and then.
That is why conducting observations with the help of home-made instruments isn't useless. They can help to make the net of observations more dense ( in space and time).
If your school has enough volunteers to make such observations, it would be useful to get in touch with the Meteorological service and raise the level of your observations to match the government-accepted standards.
