GAOTek Optical Fiber Ranger with VFL for FFTx (Up to 8 Faults)

This Optical Fiber Ranger with VFL for FFTx

(Up to 8 Faults) is used to detect fiber fault locations

in FTTx network installation and maintenance and

has built-in visual fault locator function which can

detect up to 8 faults.



Key Features

  • Portable, rugged, lightweight, and easy to use.
  • Automatic Pulse Width Control design to ensure a convenient operation.
  • Easy to identify the faults location.
  • More accurate testing results and better repeatability.
  • Up to 8 fiber faults can be detected in each measurement.
  • Built-in visual fault locator (VFL), convenient to find the faults in dead zone.
  • Long battery life, up to 5000 measurements operations.
  • Dust, water and shock proof, designed for field use.


  • Testing the distance of the fiber and identifying the faults location in the fiber link
  • Locating reflective and non-reflective breaks in the fiber network
  • Inspecting repair and maintenance of fiber
  • Ideal test device for FTTx network installation and maintenance


Technical Specifications

Operating Wavelength 1550 nm (1310 nm Optional)
Fiber Type 9/125 µm SM Fiber
Optical Connector Type FC/PC
Detector Type InGaAs
Peak Power of laser ≥60 mW
Max. Displaying Distance Reflection Event 37.28 mi (60 km) (≥ 1 dB)
Non-reflection Event 12.42 mi (20 km) (≥ 2.5 dB)
Measurement Unit m
Reflection Event Dead Zone 15 m
Distance Accuracy (Reflection Event) (m) ± (2 m + 2×10-4 x Distance)
Visual Fault Locator (VFL) Wavelength 650 nm
Output Power ≥ 1 mW
Power Supply Alkaline Battery (AA 1.5 V Batteries, 3 pcs)
Battery Operating Time ≥ 5000 Measurements
Working Temperature 23 ℉~104 ℉ (-5 ℃~40 ℃)
Storage Temperature 14 ℉~140 ℉ (-10 ℃~60 ℃)
Humidity             0 %~85 % (Non-condensation)
Dimensions 7.83 in × 3.93 in × 0.19 in (190 mm ×100 mm ×5 mm)
Weight 0.99 lbs (450 g)

Packaging List

Sr. No. Item Description Quantity
1 Main Unit 1
2 User Manual 1
3 Cleaning Swab 1
4 Alkaline Battery (1.5 V) 3
5 Soft Carrying Case 1


Additional Information

 Panel and Function

Panel & Keypad

   Press this key to turn on/off the unit. Under the standby state, press this key to turn on the auto-off function, under which the unit will turn off automatically after 5 minutes idle time.

Under the test mode, press this key to test the under- test fiber and display the results in the screen. Press this key for 5 s to enter the automatic cycle test mode and “A” will be showed in the top left corner of the screen. Press this key again to exit the automatic cycle test mode.

Under the test mode, press this key to review the previous test results. Under the refractive index changing mode, press this key to increase the value of refractive index by 0.0001.

Under the test mode, press this key to review the latter test results. Under the refractive index changing mode, press this key to decrease the value of refractive index by 0.0001.

Under the test mode, press this key to review the current refractive index or change the values together with “▲/▼” keys. Press this key again to save the values and go back to the test mode.

Press this key to activate the VFL function


  1. Turn on the unit and enter the test mode.


  1. Clean the under-test fiber and connect it to the OTDR port. Please choose the correct fiber connect before connecting.

  1. Press “SCAN” to review the fiber and show the scanning progress in the screen. With the Auto Pulse Width Control Function, the unit will set the best pulse width during the scanning process and find the events within the test range.

  1. After the test, it will show the total test results.

The maximum listable events are 8 pcs. Press “▲/▼” to review the total events. The error of the reflection events is smaller; and the error of the attenuation events is relatively larger.

  1. It will show the non-events when the real test range is within the dead zone or beyond test range.

  1. When repairing the fiber, people could use this unit to identify the location of the breaks or do the automatic cycle test. Press “Scan”, unit it shows “Scan” in the screen.

  1. Show the location of the current break.

  1. The unit starts to test 5s later. When the break is successfully repaired, a different value will be showed on the screen.
  2. Press “SCAN” again to exit automatic cycle test.
  3. Press “IOR” to enter the refractive index changing mode.

11. The refractive index ranges from 1.0000-2.0000. Press “▲/▼” keys to change the values and press “IOR” key to save and exit the changing mode. User can change the value to match the different tested fiber, however, the value should be correctly adjusted according to the refractive index of the fiber under test.

12. The VFL could be used for location of the short-distance fiber faults. Before using the function, please make sure that it is not under the automatic cycle test mode. Connect the fiber to the VFL output port and press “650 nm” key, a visible red beam could be seen at the breaking point or end-face of the tested fiber. Press “650 nm” again to exit the VFL mode.

Note: Visible light source is harmful to the eyes. Do not look at the breaking point or end face of the tested fiber directly.


  • Keep the fiber output ports are clean.
  • Please clean them regularly with the pure Alcohol cotton swabs.

Dip the cleaning swab in the pure alcohol and clean the connector gently, then clean it again with dry cleaning swab

  • Keep the dust-proof cap clean and cover it after the test.
  • Turn off the unit and keep the output ports inactive when cleaning. Otherwise, it will lead to dangerous radiation harms.
  • Choose the correct fiber connector before test.
  • Take out the batteries when not in use for a long time.

Trouble Shooting

Problem Possible Reason Solution
Fail to turn on the unit Do not turn on the unit Press the “Power” key
Lower battery power Replace the batteries
Fiber length test is not accurate Poor refractive index setting Set the refractive index as per the original manufacture’s values
Polluted fiber end face Clean it with pure alcohol
Polluted output ports Clean it with pure alcohol
Wrong fiber connector Use the fiber with correct connector or hybrid adapter


  • There are laser and sensor inside the unit. Please do not point the optical sources to the sensors directly, otherwise the sensor will be damaged.
  • Do not expose the unit to the sun directly.
  • Do not look at the output ports directly when it is turned on.
  • Before “scanning”, ensure the tested fiber is well connected to the “OTDR port” or “VFL port”. Do not plug in/out the fiber during the test.


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