Overview
Visual fault locator, also called VFL for short, is an essential tool that quickly and easily locates problem areas in fiber cables. It is regarded as a part of OTDR and it is cheap. By pinpointing the exact location of the fiber damage, such as breakpoint, bending or cracking, technicians can diagnose, troubleshoot, and fix the problem effciently.

VFL
Working Principle
This device is based on laser diode visible light source, when the light injected into the fiber, if fiber fracture, connector failure, bending over, poor weld quality failure by launching the light of the fiber to fiber fault visualization positioning.Visual Fault Locator launched a continuous wave (CW) or pulsed mode. The typical frequency of 1Hz or 2Hz, but can also work in the kHz range. Usually the output power of 0dBm (1mW) or less, the working distance of 2 to 5km, and to support all the common connector.

Types
Visual fault locators generally include the pen type, handheld type and portable visual fiber fault locator. In addition, designed with a FC, SC, ST adapter, VFL is used without any other type of additional adapters, it can locates fault up to 10km in fiber cable, with compact in size, light in weight, red laser output.

Application
The visual fault locator is commonly used for fiber identification and fault location of single-mode or multi-mode fiber as well as for wavelength loss testing. It is also an ideal tool for the examination of all types of patch cords and ribbon or bunched pigtails. It is an excellent tool for the maintenance of fiber optic networks, optical systems including LAN, FDDI and ATM, telecommunications and CATV networks. It is intended for the identification,fault location of fiber optics on single mode or multimode fiber and wavelength loss testing. It can also locate the fault of OTDR dead zone and make fiber identification from one end to the other end.