Calibration fascination: PMEL’s role in the fight
Roy Ginn, 2nd Maintenance Squadron precision measurement evaluation laboratory, tests the flatness of a micrometer spindle at Barksdale Air Force Base, La., Oct. 2, 2018. The lines on the micrometer spindle indicate the surface is flat, if the optical flat was pressed on and the lines curved or formed a point, technicians would see that the surface is not flat. (U.S. Air Force photo by Airman 1st Class Sydney Campbell)