Vernier Software and Technology - Celebrating 35 years
Vernier Software & Technology
Innovative Uses

Human Respiration

We all know that when you inhale, some of the oxygen gas in that breath is converted into carbon dioxide gas and then exhaled. But how much CO2 gas is produced? Would more CO2 gas be produced if you held your breath before exhaling?

We used our CO2 Gas Sensor on its high-range setting and a BioChamber 250 to answer these questions. First, a normal breath was exhaled through the neck of the BioChamber 250, filling the chamber. A #6 rubber stopper was placed in the top vent and a CO2 Gas Sensor was placed in the neck, as shown.

Human Respiration Setup

Data collection was initiated with the results shown. This normal breath produced a CO2 gas concentration of around 48,000 ppm. For the second run, the subject held her breath for 30 seconds prior to exhaling into the chamber. A CO2 gas concentration of 65,000 ppm was measured.

Human Respiration Graph

The final run, with the subject holding her breath for 60 seconds, produced a CO2 gas concentration of 76,000 ppm. Clearly, more CO2 gas was being produced the longer she held her breath.

Was the oxygen gas being consumed in the same way? She’ll have to get out her Vernier Oxygen Gas Sensor and start experimenting!

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