Airman 1st Class Collin Dunn, 28th Logistic Readiness Squadron fuels laboratory technician, measures the electric resistance of a fuel sample during a bottle method test at the Fuels Lab on Ellsworth Air Force Base, S.D., March 22, 2012. Lab technicians ground fuel samples to prevent the risk of fire or explosion, during these measurements. (U.S. Air Force photo by Airman 1st Class Kate Thornton/Released)