OTDR (Optical Time Domain Reflectometer)
An optoelectronic instrument used to characterize an optical fiber. It is used for testing the integrity of fiber optic cables by verifying splice loss, measure length and find faults. OTDR sends pulses of light into optical fibers at a wide range of pulse widths, and analyzes the little amounts of light reflected back to them from faults in the fibers. It then uses complex computations to determine the losses and distance to events encountered in the fiber. Included in the OTDR is a built-in power meter to test long and short fiber cables and confirm the quality of fibers.