Radon: Is it Under Your Feet?
My project is an engineering project with the goal of building a radon detector. I hope to build an accurate radon detector for a lower cost than a store-bought detector. I would consider it accurate if it has a coefficient of determination value of 0.8 or higher compared to a store-bought detector. Being able to construct a good radon detector for a lower cost would be useful so that people can know if they need to install a ventilation system in their homes. Also, the detectors are usually only used once or twice, so why would someone want to spend $200 on a product when they can make something that gets the job done for only $60 plus tools such as a multimeter and soldering iron?
My first model did not work too well, but the second was semi-functional. At the beginning, it worked as expected, but later on it lost accuracy likely due to changes in ambient radiation from coal. Then I constructed a twin to version 2, but kept it from changing enviroments, in a coal-less house. It worked the whole time, while the other slowly regained accuracy. My fourth model was made with a smaller can, so that it was eaiser to use, but it was clearly inaccurate.
Pictures of my devices:
To make my graphs, I used the ∆V from my 2-3 data points daily and averaged them together for the dependant variable of my graphs. For the independent variable, I used the radon measurements from the commercial detector. I then had R2 calculated, which then represented the accuracy of my detector as a percent correlation to the commercial readings
Graphs of my data:
My goals were to make a radon detector for at most half of the cost of a store-bought detector, and for it to have a R2 value of .8 or higher. I have met both of these goals for two of my detectors. The detector that I built only cost about $31.77 in consumable parts, while the official detector cost $199.99. I was able to build my detector for 16% of the cost of the commercial detector. Also, two of of my detectors started out with a R2 value over .8 before the one detector got contaminated and started becoming inaccurate. They had values of .92 and .87, which are both greater than .8. However V 4, the smaller can, had a failing value of .54.