Knowing which direction the wind is blowing from can be important for predicting the weather in your area.
This video shows how to make a smaller barometer that is accurate enough for weather prediction and will look nice on a shelf. It is possible to make a scientifically accurate barometer using water, but the tube must be very long. However, mercury is not only expensive to obtain, it is highly toxic to work with. Traditional liquid barometers are made using mercury as the liquid. If the needle is rising it indicates rising pressure and fair weather is on the way. If the needle is lower than the last time you looked at it, there may be a storm coming. The homemade barometer does not have to be calibrated in atmospheres or Inches of Mercury to make predictions, rather, observe the change in the reading. What makes this project even more interesting is that your homemade barometer is actually useful for making short-term weather predictions. Simple aneroid barometers are quite easy to make as you will see in the video. We are including this second link which shows how commercial and scientific grade thermometers are made.Įxperiment #3: Making and Using Homemade BarometersĪs you may recall from our discussion of weather instruments, there are two common types of non-electronic barometers, the liquid barometer and the aneroid barometer. What keeps the bottle thermometer from being a useful weather instrument is the difficulty in calibrating the instrument and devising an accurate and readable scale. However, either glass or plastic will work for demonstration purposes. The problem with the plastic is that it is flexible so it is easy to get a higher reading if you accidentally squeeze the bottle.
Some people have made these thermometers using plastic water bottles. There are many variations on this weather experiment, and it is very simple to do with just a few materials that you probably have around the house. This demonstration shows us how a liquid thermometer works. Weather Experiment #2: A Homemade Thermometer The pressure release is very sudden in the bottle while it happens rather slowly in nature, but the results are basically the same. The mechanism of this weather experiment is to pressurize the air inside the bottle and then releasing it.
What happens inside of the bottle is very similar to what occurs in the atmosphere. Have you ever looked up at a cloud and wondered how a cloud is made and how it gets up there? In this simple demonstration, we will see the process in miniature inside of a 2-liter soda bottle.