A uni-directional test will be conducted on all pigtail splices with no greater than a. 8 dB after 5 repeated attempts results in the replacement and re-splicing of that pigtail. Optical fiber, short for optical fiber, is a fiber made of glass or plastic that acts as a light-transmitting tool. The transmission principle is 'total reflection of light'. Generally, a light-emitting diode. To be able to judge whether a fiber optic cable plant is good, one does a insertion loss test with a light source and power meter and compares that to an estimate of what is a reasonable loss for that cable plant. There are various possibilities: Mechanical splicing means that two fiber ends are tightly held together with some mechanical means. An Optical Power Meter and Laser Light Source will be used to measure power loss on each completed ring or distribution span to verify continuity between fibers (no fibers incorrectly spliced. At TREND Networks, we are frequently asked how much loss is allowed when conducting testing on fiber optic cabling. patchcords, with negligible fiber loss, the measured loss may be considered the loss of the connector mated to the reference connector.