Perform a visual inspection of the coupler and fiber adapter to check for any visible defects, such as scratches, cracks, or contamination. Testing a splitter or other passive fiber optic devices like switches is little different from testing a patchcord or cable plant using the two industry standard tests, OFSTP-14 for double-ended loss (connectors on both ends) or FOTP-171 for single-ended testing. If it's a long outside plant cable with intermediate splices, you will probably want to verify the individual splices with an OTDR test also, since that's. These types of situations require a basic understanding of fiber couplers to ensure proper signal strength for network dependability and validity. These high-speed, high-capacity communication networks are increasingly replacing copper cables, offering superior performance and.