We have been working super hard on completing our CO2 sensor over the last week or so. Once we designed the circuitry and tested it successfully on a bread board, we soldered it on to a PCB. Here’s what the final PCB looks like:
In case you’re wondering, the golden box-like structure on the left of the PCB is the CO2 analyzer. It shines an infrared light and measures how much the intensity of the beam falls in order to calculate the amount of CO2 in the analyzer.
Once we made sure the circuitry was working fine, we started building the physical setup on which we would mount the sensor. To do this, we hit the Mudd machine shop and started battling with the 3D printer.
After hours of battling, we emerged victorious and the printer gave us the following part on which we are going to mount the membrane which separates dissolved gases from the surrounding waters of the lakes.
After all of this, we tested for 2 things. First, if our physical setup leaked at all. We did this by dunking our work into a sink full of water and then checking the inside of the PVC (where we are going to mount all our circuitry) if any water had collected. Second, we checked if the sensor was still working fine after being integrated with the newly constructed parts. On both counts, we were good after some back and forth trouble shooting.
Next feat — actually calibrate this sensor. Currently, it displays trends in CO2 rise and fall, but it doesn’t give us sensible numerical representations of the CO2 concentration in the room. Watch out for the next blog to hear about our calibration adventures!