Optical fault locator

How to Choose a Visual Fault Locator That Suits Your Needs?

Have you ever wondered why optical fiber networks, despite being highly modern, still encounter issues like breaks, bends, or poor contacts? These are optical faults—issues occurring within the fiber cable that cause signal attenuation or transmission interruptions. In such cases, accurately detecting the fault location becomes the top priority for rapid repair, avoiding impacts on the entire system.

Is It Easy to Detect Optical Faults?

A Visual Fault Locator (VFL) acts as a "visual eye," allowing you to easily see where the optical fiber is damaged. This device uses a red laser with a wavelength of approximately 650nm to detect signals escaping from fault points, thereby identifying errors quickly and accurately.

In practice, the VFL is not only useful for telecom technicians but is also applied in optical transmission network maintenance, CATV system installation, fiber internet, and high-tech infrastructure projects. With the flexibility of field use, models like the UNI-T UT691-10, SKYCOM Shinho T-VF210, or 3S Telecom VFL-30B support fault detection ranges from 8 to 16 km with laser power ranging from 10mW to 30mW, suitable for various scenarios.

How a VFL Detects Optical Faults

A Visual Fault Locator operates on the principle of injecting a red laser beam (650nm) into the optical fiber and tracing light leaking at fault points such as breaks, sharp bends, or poor splices. When the laser travels along the fiber, the damaged area emits visible light, helping to pinpoint the exact location.

Some machines possess two main lighting modes: Continuous Wave (CW) and Flashing (Pulse) mode, helping users easily detect faults via the naked eye or infrared cameras. For example, the UNI-T UT691-10 offers both modes to increase sensitivity during inspection. You can choose the appropriate mode depending on lighting conditions and the type of fault.

How to Choose the Right Visual Fault Locator?

Selecting a VFL that fits your actual needs is not as simple as picking the machine with the highest power or highest price. You need to consider several technical factors and practical applications to make a wise investment.

Fault Detection Distance: If you only work with fiber systems within a short range of 2–5 km, devices like the UNI-T UT691-10 are sufficient. Conversely, if you need to survey long cable routes from 8 to 16 km, the 3S Telecom VFL-30B (30mW, 16km) would be more suitable, ensuring the laser is strong enough to detect faults accurately at long distances.

Laser Power and Safety: Laser power directly affects the penetration capability and sensitivity of the VFL. However, higher power requires more attention to safety during use to avoid eye injury. Devices like the SKYCOM Shinho T-VF210 have power starting from 10mW, suitable for technical experts familiar with laser safety procedures.

Additional Features and Design: You should prioritize machines with multiple beam modes (continuous, flashing), low battery warning, and Auto Power Off (APO) after inactivity. For instance, the UNI-T UT691-10 features a battery capacity of up to 1050mAh, allowing for over 7 hours of continuous work, along with IP54 dust and water resistance, which is very convenient for outdoor use.

Connectors and Accessories: VFLs typically use a standard 2.5mm connector, compatible with most common connector types like FC, SC, and ST. You should also consider the included accessories.

Choosing the right visual fault locator will help you optimize technical efficiency and investment costs. From selecting power and detection distance to support features, you should carefully consider the practical requirements of your job.