Senior Airman Christopher Johnson, 47th Flying Training Wing Precision Measurement Equipment Laboratory technician, works on a broken watt meter calibrator, at the PMEL shop on Laughlin Air Force Base, Texas, Feb. 26, 2013. PMEL technicians work to ensure that measurement equipment ranging from scales at the base gym to aircraft gauges provide accurate information. (U.S. Air Force photo/Senior Airman Nathan Maysonet)