In defining the experiment, a list was first made of everyday activities that occur at gas stations. Those activities include for example sliding across the car seat, taking a hat off, removing your cell phone or wallet from your pocket, rubbing your cell phone against your hair, removing a sweater. A list of materials that rub together during these activities was generated. After gathering samples of the materials, combinations of materials were rubbed together and an electrostatic voltmeter was used to measure the static voltage that had been generated. The experiment was performed on both a high and low humidity day.
Standard deviations were consistently on the order of 33% of the average value for all measurements, indicating acceptable experimental variation. The plots of voltage versus material combinations showed good agreement with that predicted using the triboelectric series. An additional experiment was run to investigate one major discrepancy with that predicted. Tests run on a low humidity day showed higher average voltages compared to tests on a high humidity day, as expected. Combinations of materials which generated in excess of the 1000 volts which could cause a static discharge to ignite gas fumes are identified on the plots. Polypropylene and hair created the biggest voltage.
My conclusion is that there are a number of material combinations which can create a danger when rubbed together during normal activities while pumping gas. While signs at gas stations warn people not to use cell phones while pumping gas, there are other common activities besides using a cell phone that are potentially dangerous.
The purpose of this project is to investigate dangers at gas pumps from static charge build-up that can result from normal things people do.
Science Fair Project done By Anna K. Nowak