Optical Visual Fault Locator electro base FLT-125 25 mW, max range 18–20 km, connectors SC/FC

The electro base FLT-125 Visual Fault Locator (VFL) is a handheld fiber-optic test tool that emits a 25 mW visible red laser for tracing faults and checking continuity in single-mode fiber networks. Designed for field technicians, the FLT-125 provides a bright continuous or pulsed light source and accepts SC and FC connectors for direct coupling to patch cords and terminated fiber ends. The unit's indicated maximum effective loss-check range is 18–20 km under typical conditions, allowing technicians to locate breaks, macrobends and faulty splices along long fiber runs.

Advantages

The FLT-125 offers a high-power 25 mW red laser that produces a clearly visible light through fiber imperfections and breaks, improving the speed of locating defects. Support for both SC and FC connectors enables flexible connection to common fiber cabling without additional adapters. Continuous and pulsed emission modes help to distinguish the test signal from ambient light and to identify multiple fault points along a fiber. The compact, field-oriented design simplifies on-site testing and rapid fault isolation.

Suitable for

• Locating breaks and visible faults in single-mode fiber runs
• Tracing fibers through patch panels and cable ducts
• Checking continuity after splicing and connector installation
• Verifying fiber routing in building and campus networks

Key specifications

• Visible wavelength: red laser
• Output power: 25 mW
• Effective maximum range for loss-check: 18–20 km (indicated)
• Supported connector types: SC and FC
• Emission modes: continuous and pulsed
• Fiber type: single-mode

How to use

Connect the FLT-125 to the fiber under test using the appropriate SC or FC connector. Power on the unit and select continuous or pulsed emission depending on the environment and visibility needs. Route the fiber or inspect along the cable path; visible red light will escape at breaks, severe bends or faulty splices, making fault locations apparent. For inline checks, couple the VFL to one end of the fiber and inspect access points, patch panels and junctions along the route for visible light indications.

Usage recommendations

Do not look directly into the laser output or point the laser at people. Use the pulsed mode in bright environments to improve visibility. Ensure connectors are clean before testing to avoid false indications and to protect the unit's ports. For safety and accurate range assessment, consider ambient light conditions and fiber attenuation when interpreting visible signal strength.