Our group conducted research to determine if there is any correlation between how much energy a cell phone uses and how much radiation it emits. We recorded the energy used by measuring the amount of power necessary to run the phone while it made a one minute phone call. The power ran from the wall through the Watts Up Pro to the phone charger, and finally to the phone. This gave us the number of watts used, displayed in the table below. We measured the radiation emitted using the RF meter, which gave us radiation in volts per meter.
Watts Used | Max Radiation (V/m) | Phone Type | Smart Phone? |
2.0 | 0.465 | Droid Incredible 2 | Yes |
2.4 | 0.720 | Verizon LG | No |
2.6 | 0.783 | Verizon flip phone | No |
3.0 | 2.087 | Verizon LG | No |
3.7 | 1.929 | Droid 1 | Yes |
3.8 | 1.361 | Verizon LG | No |
4.0 | 1.843 | Verizon LG | No |
4.3 | 0.884 | Droid 2 | Yes |
4.4 | 3.145 | Samsung | No |
4.5 | 1.262 | Droid X | Yes |
5.0 | 1.333 | Droid 2 | Yes |
5.0 | 0.992 | iPhone 4 | Yes |
5.1 | 2.111 | iPhone 4 | Yes |
6.0 | 1.507 | iPhone 4S | Yes |
Our data shows that phones that use fewer watts do, in fact, emit less radiation. The graph displays that there is some correlation. However, to identify this trend conclusively more research is required. The data suggests that smart phones use, on average, more energy than phones without those capabilities, known as feature phones. Six of the top seven power-using phones we tested were smart phones, while the majority of the remainder were feature phones. While the smart phones may use more power, they don’t appear to emit more radiation. It is possible that phone makers work harder to reduce the amount of radiation emitted by their more expensive models. A potential source of error in our experiment could be that we tested phones of different service providers. Phones with bad service in the area we tested them (the Retreat) probably had to work harder (and use more energy) to get service during the call. To find a true correlation, if there is one at all, we would need to take more data and take phone providers into account. Our data suggests that there may be a correlation, which certainly warrants more investigation.
This was a timely experiment that opens up many different opportunities for follow-up experiments. Everything is very well explained, and the data is quite clear.
Your project makes me curious as to what the mechanisms are inside of phones that cause energy to be converted into radiation. Perhaps if a group follows up on this project next year, they could look at what exactly these smart phones seem to be doing that makes them so efficient (in terms of minimizing radiation per energy intake.) Another possibility for a follow up experiment might be simply increasing the sample size, and controlling for conditions such as location, and any background programs that might be running on the phone.
This is sort of an aside, but I’m curious what your instruments looked like, because I don’t think I’ve ever seen what an RF meter or Watts Up Pro are like. Perhaps you guys could put up pictures next time! (Or some details about how they work, although maybe it’s fairly straightforward.)
Also, it may have been useful to run a “T-Test” (or any sort of test that uses variance/standard deviations) to see just how significant your data was. Or perhaps a “correlation coefficient” would be more appropriate here.
Overall I thought this was a really good project and presentation, and while it might not scare me away from my IPhone, I certainly feel enlightened on the subject.