Huawei Optical Time Domain Reflectometer Usage

A Huawei OTDR is used to test fiber optic networks by sending light pulses through the fiber and analyzing reflections to measure loss, locate faults, and verify fiber quality.Step 1: Prepare the OTDR and Fiber

• Clean all connectors and ports using alcohol to remove dust and contaminants; avoid other detergents or refractive index matching liquids that may damage the fiber connector .
• Connect a launch cable (a known-good reference fiber) between the OTDR and the fiber under test. This helps eliminate the "dead zone" at the beginning of the trace and ensures accurate measurement .

Step 2: Power On and Configure

• Turn on the OTDR and select the wavelength appropriate for your fiber (commonly 1310 nm, 1550 nm, or both), .
• Choose the pulse width based on fiber length: shorter pulses for high-resolution short fibers, longer pulses for long-distance fibers .
• Set the test mode:
  • Automatic mode for standard tests
  • Manual mode for short-distance or ultra-long-distance fibers where event detection may be inaccurate
  • Fault locating mode for quickly identifying obvious faults .

Step 3: Connect and Start Measurement

• Connect the launch cable to the OTDR and the fiber under test to the launch cable .
• Initiate the measurement and wait for the trace to stabilize. The OTDR will display a trace representing backscattered light along the fiber, showing reflective peaks (connectors, mechanical splices) and non-reflective losses (fusion splices, bends), .

Step 4: Analyze the Trace

• Verify trace quality: ensure minimal noise and a clearly visible fiber end.
• Automatic analysis: the OTDR can detect and characterize events, providing loss values and locations.
• Manual verification: use cursor functions to measure distances and confirm automatic event detection accuracy .
• Identify abnormal attenuation points using Rayleigh scattering (continuous along the fiber) and Fresnel reflections (at discrete interfaces like connectors), .

Step 5: Save and Document

• Save the trace files with descriptive names.
• Export event tables and summary reports for documentation and future reference .

Step 6: Interpret Results

• Reflective peaks indicate connectors or mechanical splices.
• Non-reflective losses indicate fusion splices, bends, or fiber attenuation.
• End of fiber: reflective end indicates a connector or break; non-reflective end indicates a coiled or cleaved fiber . Using these steps, a Huawei OTDR can effectively measure fiber length, loss, locate faults, and verify installation quality, ensuring reliable fiber optic network performance .