Tech Sgt. Jason Truong, 47th Flying Training Wing Precision Measurement Equipment Laboratory lab chief NCO in charge, uses a flashlight and mirror to read the serial number on an accelerometer calibrator, at the PMEL shop on Laughlin Air Force Base, Texas, Feb. 26, 2013. The accelerometer calibrator measures vibrations and serial numbers are checked to ensure each part is matched to a specific machine so measurements are consistent. 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)