CoachLab probeware systems can make a very effective weather station for the science classroom. By using sensors for relative humidity, barometric pressure, and temperature students can learn how these factors effect day to day weather. In many ways CoachLab can be a more educationally sound tool to teach weather than normal weather stations. Normal weather stations simply display or record trends in the readings taken from their sensors. Coach software has a full set of tools that can be used to analyze the data gathered from experiments. Coach also has a multimedia environment that students work in that can be used to convey information and help teach students.
1) Gather your materials
2) Set up the weather station. (works best near a window)
Our example uses a CoachLab II Interface panel connected to a computer, however if you need your weather station to be portable (or if you do not have a computer in your classroom) then you can use a ULAB, TI-CBL, TI-CBL2, or Vernier LabPro interface.
Connect the interface panel to a PC and connect each of the four sensors to the panel. The relative humidity sensor and one of the temperature sensors should be placed outside. The barometric pressure sensor can remain inside, as should the second temperature sensor.
Make sure that the sensors are not placed in such a way that they will be rained on or otherwise effected or damaged by the effects of the weather and other outdoor influences such as insects or animals. It is best to keep the temperature sensor shaded from direct sunlight. A weather instrument enclosure may also be useful.
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Creating an activity in Coach Software is a very simple task and for this activity should take about ten minutes.
The first step has already been outlined above, choosing the interface panel you will use, and choosing the sensors you will use. From there it is as simple as:
1) Set up a new project and activity (create an new, empty activity that is stored inside a project)
2) Set up sensors (Tell Coach which sensors you will be using and where they will be plugged in)
3) Set up how data will be displayed (set up graphs and tables)
4) Create on screen instructions (make a text file with instructions)
5) Set up measurement settings (in this case 24 hours at a time with measurements every minute)
6) Save the activity and then start recording data.
For detailed step by step instructions on setting up this activity with Coach Author software please click here.
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| I have tested this activity by recording weather data under controlled conditions over a 24 hour time period. In this experiment all four sensors were placed indoors in order to test my activity, which produced some interesting temperature results. Click on the image to the right to enlarge a full screenshot of Coach Software in action. |
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| Graph 1: Indoor and Outdoor Temperature In the original experiment I was going to monitor temperature in a pond and air temperature at the same spot, so this graph is labeled as "Air and Water" temperature. Both sensors were placed indoors, however one was at four feet (the red graph) and the other was at ground level (the blue graph). At seven hours into the test I moved the ground temperature probe into an air conditioning duct in order to get more interesting results. You can see that both temperature traces oscillate up and down by about two degrees. This is the action of my air conditioning turning on and off. |
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Graph 2: Relative Humidity This graph shows 24 hours of humidity data taken from indoors. An outdoor measurement would have been more accurate in terms of predicting the weather (as air conditioning does remove humidity from inside air) but the location used to test this experiment was not totally air tight so an indication of a change in humidity between 51% to a maximum of 59.5% is clearly visible. The zoom tool has been used to fit this graph to the window in order to show its details more accurately. As you can tell, alone the humidity graph doesn't tell us too much about the weather. |
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Graph 3: Barometric Pressure This graph shows 24 hours of barometric pressure data. Units are in millibars however it is always possible to use a mathematical formula in Coach in order to convert to a different pressure unit. As you can see there are two main features to this graph, one dip to a low of 1150.2 millibars and one spike at 1153.1 millibars. Knowledge about the weather tells us that if air pressure is going down then rain is likely. Conversely if the pressure is rising then that likely means fair weather. |
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Graph 4: Pressure AND Humidity In this graph, Coach put the Pressure and Humidity data into one easy to read graph. Two scales are used since 0 to 100% humidity would show up as a practically flat line compared to 1150 to 1154 millibars if displayed together on the same scale. Our goal is to see how pressure and humidity react during a weather event. In this case a thunderstorm and rain over a starting at 2 hours, and continuing on till about 16 hours. More rain followed after 24 hours. See how the pressure and humidity graphs together can tell the story? |
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Obviously if I had placed one thermometer and the relative humidity sensor outside (not inside my temperature controlled, enclosed office) then the data would have been even more useful and interesting. If you use this activity in your class you might wish to record weather data any time strong storms move through your area, including snow, rain, thunderstorms, etc. You might even let it run continuously and ask students to make a prediction (using the predict tool) on what pressure and humidity will do over the next few hours (based on manual wind measurement and cloud watching) to determine when it will likely start to precipitate.
Showing them the temperature plot of indoor temperature and the effects of air conditioning (the oscillations in the graph indicating when the AC turned on, when it turned off, how the air heated back up, and then how it cooled back down) is also a good way to introduce the concept of hysteresis (time delays) in control mechanisms.
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CoachLab has many tools that are useful in viewing and analyzing data. When viewing weather data you may wish to:
Data from Coach can also be exported to spreadsheet programs in order to build large data bases of weather information in order to view longer term trends, compare seasons, and perform more detailed analysis.
Graphs can also be cut and pasted into other programs in order to create lab reports, or a daily weather forecast that can be posted to a website.
Internet links can be embedded into the Coach activity also, so you can link to weather data from your state, community, school, local TV station, or the weather channel.
To learn more about Coach's tools and features please visit our software tour by clicking here.
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