Yes, OTDR can be used to test fiber optic cables that are already in use. In fact, this is one of its most common applications. Because optical fibers can be bent, crushed, stretched or otherwise damaged during use, the performance and condition of fiber optic cables need to be tested periodically to ensure their reliability and stability.
When testing a used fiber optic cable, the OTDR emits a short pulse of light signal into the cable and measures the intensity and time delay of the reflected light. By analyzing the characteristics of the reflected light, the OTDR can determine information such as connection points, losses and defects in the fiber optic cable. If there is a problem with the fiber optic cable, OTDR can help determine the location and nature of the problem so that it can be repaired or replaced.
When testing used fiber optic cables, it is important to note that the performance of the cable may have been compromised and therefore the test results may be affected to some extent. In addition, testing needs to be done carefully to avoid further damage to the fiber optic cable. Therefore, it is recommended that the test be performed by a professional technician to ensure the accuracy and safety of the test.
