Requirements for the format of optical fiber splicing chromatogram

An optical fiber splicing chromatogram must clearly display splice locations, measured losses, fiber lengths, and reflectance values, following bidirectional OTDR testing and standardized labeling conventions.

Key Requirements

1. Trace Presentation

• The chromatogram should show a continuous OTDR trace with distance on the horizontal axis and backscatter or reflected power on the vertical axis .
• Splice points must be clearly marked, typically with a symbol or annotation indicating the measured splice loss in dB .
• Connector reflections, fiber breaks, and other events should be distinguishable from splices. 2. Measurement Standards
• Bidirectional testing is required: traces must be recorded from both ends of the fiber and averaged to eliminate artifacts such as "gainers" or exaggerated losses .
• Splice loss should be measured according to ANSI/TIA/EIA-455-8 or equivalent procedures, ensuring accuracy and repeatability .
• The OTDR settings (pulse width, wavelength, index of refraction) must match the fiber type and span length, typically at 1310 nm and 1550 nm for single-mode fibers . 3. Data Annotation
• Each splice should include:
  • Distance from the OTDR launch point
  • Measured insertion loss
  • Event type (splice, connector, break)
• The chromatogram should include fiber identification, test date, and equipment calibration reference . 4. Documentation and Reporting
• Chromatograms should be legible and reproducible, suitable for QA/QC review and contractual acceptance .
• Pigtail tests require a 1-km launch reel to accurately measure connector and adjacent splice losses .
• The report should indicate whether the splice meets ITU-T L.12 or other applicable standards for splice loss and mechanical integrity . 5. Optional Enhancements
• Visual Fault Locator (VFL) verification can supplement OTDR traces to confirm splice quality visually .
• Modern OTDR software may include automated loss estimation and event labeling, which should be included in the chromatogram output for clarity .

Summary

A compliant optical fiber splicing chromatogram must provide a clear, annotated OTDR trace showing all splices, connectors, and events, with bidirectional loss measurements, proper calibration, and standardized labeling. This ensures accurate assessment of splice quality, adherence to ITU-T and ANSI/TIA/EIA standards, and reliable documentation for network deployment and maintenance .