Biosensor Array Carbon Dioxide Output
Carbon dioxide output sensor
I was able to calibrate the carbon dioxide sensor earlier today. In the process, I also learned that the sensor is much simpler than I originally thought. For our purposes, the sensor will require a total of three connections:
- a common ground
- a source of between 6 and 12 VDC, at about 150 milliamps
- an analog sink for between 0 and 4 VDC at very few milliamps of current
The 6 to 12 volts enables the onboard sensor heater and the output signal. The output signal is an analog voltage which is inversely related to the amount of carbon dioxide present at the sensor. In other words, as the amount of carbon dioxide increases, the output voltage decreases. The sensor appears fairly sensitive and responsive and seems to support a sample rate of up to twice per second. Based on these details, we should be able to both identify the changes in the peak carbon dioxide output of the subject and measure the time between the nth and (n + 1)th peaks, to infer an exhalation rate.