Sperry Rail Service (reporting mark SRSX) is a rail inspection company founded in 1928 by Elmer Ambrose Sperry. The company was the first in the world to offer nondestructive testing of railroad track. Since its formation, Sperry has been contracted by most of the major railroads in North America to inspect rail. To accomplish this task, the company operates a fleet of rail service vehicles that travel along railroads to detect defects. While most prominent in North America, Sperry operates on every continent.