Testing a pigtail fiber involves using a power meter and light source or an OTDR with a launch cable to measure continuity, splice loss, and attenuation accurately.

Equipment Needed

• Optical Power Meter and Laser Light Source: For measuring end-to-end loss and verifying continuity .
• Optical Time Domain Reflectometer (OTDR): For analyzing splice loss, connector loss, and fiber uniformity .
• Launch Cable (1 km recommended): Ensures accurate measurement of connector and splice loss near the distribution panel .
• Temporary Fusion or Mechanical Splice Tools: For connecting the pigtail to the fiber under test .
• Cleaning Supplies: To clean fiber ends and pigtail connectors before testing .

Step-by-Step Procedure

Using a Power Meter and Light Source

1. Prepare the Pigtail: Clean the pigtail connector and the fiber end.
2. Connect the Light Source: Attach the pigtail to the light source.
3. Connect the Fiber Under Test: Use a temporary fusion or mechanical splice to connect the pigtail to the bare fiber.
4. Measure Power: Record the output power at the far end using the power meter.
5. Calculate Loss: Compare the measured power to the reference power to determine attenuation or splice loss. Ensure the splice is well-cleaved and, if necessary, renew index-matching gel .

Using an OTDR

1. Clean and Connect: Clean the pigtail and connect it to the OTDR test port. Ensure the convex U-shaped part of the pigtail fits properly into the OTDR socket .
2. Select Wavelength: Choose 1310nm or 1550nm depending on the fiber type .
3. Set Test Distance and Pulse Width: Set the distance to about 1.5 times the fiber length and select a pulse width appropriate for the fiber length (shorter for <10 km, longer for >10 km), .
4. Use a Launch Cable: Connect a 1 km launch reel between the OTDR and the pigtail to accurately measure connector and splice loss .
5. Take a Trace: Run the OTDR trace and analyze the loss between markers to determine splice and fiber attenuation .
6. Verify Splice Loss: If a splice exceeds 0.30 dB, re-splice until it meets the standard; maximum acceptable loss is 0.35 dB .

Best Practices

• Always clean fiber ends before testing to avoid contamination.
• Use a good cleaver for temporary splices to ensure reliable measurements .
• Calibrate power meters before testing to ensure accurate readings .
• Avoid using long patch cords or improper adapters for pigtail tests, as they can introduce measurement errors . By following these steps, you can accurately test pigtail fibers for continuity, splice quality, and attenuation, ensuring reliable fiber optic network performance.