Connect the test cord directly from the light source to the power meter. Set the meter to 0 dB (this is your reference). Connect at the source end . An optical power meter is a key tool that measures light strength in the fiber, helping identify signal losses or connection problems. This guide will explain how to use an optical power meter effectively for network installation, troubleshooting, and performance checks. Before using an optical. How to Test Fiber Optic and Ethernet Cables with Optical Multi meter. The basic process is straightforward: turn the meter on, set it to the correct wavelength, clean your connectors, plug in, and read the. Connect the light source and power meter with a high-quality reference cable.