They allow two cables with connectors to mate. They are also very important to good loss testing as they contribute to the mated connector loss. Don't use the ones with plastic inserts for testing as they wear out quickly. Use only those with metal or ceramic alignment sleeves. You can get hybrids too, to mate ST to FC or SC connectors to simplify testing different connector types.
Cleaners are necessary to clean connectors and fibers for testing and termination.
OTDRs are instruments that are useful to verify splice loss and find faults in cable runs. They are expensive, but sometimes invaluable. You can teach yourself fiber optics with our free online training program, Fiber U Online . If you are taking the Fiber U Online Course, Click here to return to the lesson plan. Lennie Lightwave and Fiber U are registered service marks of fotec, inc .