How to Make a Simple Spirometer
Spirometers are used by those with respiratory disorders to measure lung capacity. They show how much air can be taken in and released by the lungs, and their readings are used to examine lung function. Spirometers are most often used by asthmatics to monitor their condition, but doctors can also use these devices to diagnose certain conditions. Most spirometers are electronic in nature. This simple, homemade spirometer is meant only for experimental purposes and should not be used to diagnose or monitor any medical condition.
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Things You'll Need
- 2-liter plastic soda bottle
- Masking tape
- Waterproof marker
- Large beaker with measurement lines
- Deep bowl
- 1- to 2-foot-long piece of plastic aquarium tubing
Instructions
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Making the Spirometer
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1
Unscrew the cap from the soda bottle. Pour out any soda and rinse thoroughly. Peel off the label and apply a piece of masking tape vertically along the side of the bottle.
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2
Use the beaker to pour water into the empty soda bottle, 60 ml at a time. After adding each increment of water, mark the water level on the masking tape with the marker. Continue until the bottle is full of water.
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3
Clean the bowl and pour in about 4 inches of water. Screw the cap onto the full soda bottle and invert it in the bowl, so that it's resting on its cap.
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4
Unscrew the cap on the bottle while it's underwater by tilting the bottle to one side. Some of the water will be released into the bowl.
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5
Slide one end of the aquarium tubing into the open mouth of the bottle. Hold the other end in one hand above the bowl. Use your other hand to support the bottle.
Using the Spirometer
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6
Support the bottle with one hand, and grip the free end of the plastic tubing with the other. Have a partner keep an eye on the bottle's markings.
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7
Inhale as much air as possible and blow steadily into the tubing until completely exhaled; the water will bubble up in the bottle. Have the other person take note of which line the bubbles in the bottle hit while exhaling.
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8
Count the lines, from the opening in the bottle up to the line the bubbles hit. Multiply the number of lines by 60. The resulting number is your lung capacity.
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1
Tips & Warnings
Never use this spirometer to diagnose or monitor medical conditions. It's meant for use in science experiments only.
