Ensuring the optical integrity of the OPGW is crucial. "Fiber optic continuity testing tools" are used at various stages of stringing:

• Visual Fault Locators (VFLs): Emit a visible laser light into the fiber. Any breaks, sharp bends, or poor connections will cause the light to escape, allowing for quick visual identification of issues.

• Optical Loss Test Sets (OLTS) / Power Meters & Light Sources: Measure the overall optical loss (attenuation) of the fiber segment. This confirms that the signal strength is within acceptable limits after stringing, indicating no significant damage.

• Optical Time Domain Reflectometers (OTDRs): These are advanced tools that provide a "picture" of the fiber length. They can pinpoint the exact location and severity of breaks, splices, or other defects within the fiber, allowing for immediate corrective action during or after stringing.

These tools provide immediate feedback, preventing costly reworks after installation and guaranteeing the communication functionality of the OPGW.