A simple method of testing the length of lung capacity of a human is to use plastic tubing, a clear plastic bottle and a tank of water. Mark the bottle with incremental measurements in milliliters. Fill the bottle with water, and then place your hand over the top of the bottle. With your hand over the top of the bottle, flip the bottle and place it top down into the water tank. Once the bottle is submerged, remove your hand from the top. The water will remain in the plastic bottle. Have a friend hold the bottle upright in the water tank. With the bottle still submerged, place the plastic tubing inside the mouth of the bottle. Be sure to squeeze the tubing so that no air enters. Have a subject exhale with normal breathing into the tubing. Water will be taken from the bottle and placed into the tank. Have each subject perform this experiment three times, and record the amount of water that was displaced each time.
For this experiment, you will need a balloon and a metric ruler. Have your test subject inhale and exhale normally into the balloon. Measure the diameter of the balloon. Have the subject repeat the steps three times, and record the average of each diameter. This experiment can be used to compare the lung capacities of different types of people. Try a variation by having your subjects divided into groups based on age. Record the results of each group, and see if you can derive your results from the experiment based on how lung capacity changes when you get older.
For testing the lung capacity of yourself or others, it may be a good idea to compare the length of the lung capacity of different groups of subjects. Choose subjects that vary with age, sex, athleticism, weight and other characteristics that you think may affect the lung capacity in a human such as playing a woodwind instrument. To start the experiment, record the statistics of each subject that you choose to participate. You will need to compare their results at the end of the experiments.
Make your science experiment stand out from the others by delving deeper into the information. Compare the results of your subjects based on their age, gender or fitness level. Run a second experiment on your subjects that requires them to run in place for 30 seconds before blowing into the tube or balloon. Compare these results to their original results to show how lung capacity can change with activity.