Improved CO₂ Gas Sensor Allows for Studies of 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 new 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.

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. 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!

BioChambers Enhance Experimentation

Many of you have used our CO₂ Gas Sensors to study the respiration rate of germinating peas. Now, with the BioChamber 250, it is easy to connect an O₂ Gas Sensor simultaneously as shown below. Simply soak some peas for a few hours and place them in the chamber. Connect the two sensors and begin data collection. The graph below shows the impressive results, utilizing Logger Pro's capability of adding a second y-axis on the right side.

The BioChamber 2000, the 2 liter version shown below, opens the door to an unlimited variety of experiments with its larger volume and easy-access lid.

• CO₂ Gas Sensor | Order Code CO2-BTA | $249
• O₂ Gas Sensor | Order Code O2-BTA | $188
• BioChamber 250 | Order Code BC-250 | $6
• BioChamber 2000 | Order Code BC-2000 | $19