VISUAL FAULT LOCATOR

A compact red-laser Visual Fault Identifier / Visual Fault Locator for tracing fibers, checking continuity and visually locating bends, breaks and connector faults in single-mode and multimode networks.

A Visual Fault Locator sends visible red light through an optical fiber. At sharp bends, breaks or poorly mated connector points, light can escape from the fiber and make the problem visible to the technician.

The VFI4 is intended for quick continuity checks, fiber tracing, splice verification, connector validation and fault finding around fiber cabinets and patching points where OTDR blind spots or dead zones can make very short events difficult to resolve.

Choose Configuration

VFI4 High Power

Part NumberVFI4-01-0900PR

High-power AFL VFI4 Visual Fault Identifier.

Output Power
5mW max
Published Range
Up to 10km
Laser Class
Class IIIa (FDA) / Class 3R (IEC 60825-1:2014)
Included Adapters
2.5 mm + 1.25 mm universal adapters
Battery Life - Flash Mode
<30hours

Locate Visible Faults Quickly

Identify bends, breaks and poorly mated connectors by looking for visible red light escaping from the fiber path.

Trace and Identify Fibers

Use the visible source for end-to-end continuity checks and identifying fibers in patch panels or during splicing work.

Complement OTDR Testing

Use the VFI4 to find short-range faults inside an OTDR dead zone.

Carry a Compact Field Tool

The 43 g VFI4 fits in a compact 7.9 × 5.1 × 2.2 cm housing and operates from a single AA battery.

Feature VFI4 High Power VFI4-L Low Power
Output Power 5 mW maximum 1 mW maximum
Published Range Up to 10 km Up to 4 km
Laser Class Class IIIa (FDA) / Class 3R (IEC 60825-1:2014) Class II (FDA) / Class 2 (IEC 60825-1:2014)
Included Adapters 2.5 mm + 1.25 mm universal adapters 2.5 mm universal adapter
Battery Life – Flash Mode <30 hours <50 hours
AFL Part Number VFI4-01-0900PR VFI4-02-0900PR

Fiber Identification & Tracing

Identify and trace fibers during activation, installation and patch-panel work.

Continuity Checks

Perform quick end-to-end continuity verification before more detailed optical testing.

Connector Troubleshooting

Identify poorly mated connectors and visually validate mechanical connector installations.

Splice Verification

Use visible light during splicing operations to help identify fiber paths and gross faults.

OTDR Dead-Zone Troubleshooting

Locate visible faults close to connectors or events that may fall inside an OTDR dead zone.

Parameter VFI4 VFI4-L
Emitter Type Laser, Class IIIa FDA 21 CFR 1040.10 / 1040.11; Class 3R IEC 60825-1:2014 Laser, Class II FDA 21 CFR 1040.10 / 1040.11; Class 2 IEC 60825-1:2014
Wavelength 650 nm ±15 nm 650 nm ±15 nm
Output Power 5 mW maximum 1 mW maximum
Modulation 2 Hz or CW selectable 2 Hz or CW selectable
Power 1 × AA battery; <30 hours flash mode 1 × AA battery; <50 hours flash mode
Operating Temperature -10°C to +50°C, 85% RH non-condensing -10°C to +50°C, 85% RH non-condensing
Storage Temperature -30°C to +60°C, 95% RH non-condensing -30°C to +60°C, 95% RH non-condensing
Size (H × W × D) 7.9 × 5.1 × 2.2 cm 7.9 × 5.1 × 2.2 cm
Weight 43 g 43 g
AFL VFI4 and VFI4-L optical and general specifications with ordering information
Adapter Use AFL No.
2.5 mm Universal For VFI port; supports connector formats such as FC, SC and ST 2900-50-0013MR
1.25 mm Universal For VFI port; supports LC and MU connector formats 2900-50-0012MR

The 1.25 mm universal adapter is included with the VFI4 High Power model only. Verify accessory requirements when specifying the VFI4-L.

  • CE Marking
  • IEC 61010-1
  • EN 61010-1
  • IEC 61326-1
  • EN 61326-1
  • EN 55011
  • FDA 21 CFR 1040.10 / 1040.11
  • IEC 60825-1
  • RoHS 2
  • RoHS 3
AFL VFI4 qualification table showing CE safety EMC laser safety and RoHS compliance
Description AFL No.
VFI4 Visual Fault Identifier with 2.5 mm and 1.25 mm adapters VFI4-01-0900PR
VFI4-L Visual Fault Identifier with 2.5 mm adapter VFI4-02-0900PR

Frequently Asked Questions