Where selection starts
Define the measurement task before choosing launch-fiber length. Review instrument settings, end connectors, fiber under test and the near-end event evaluation objective together.
- Decision to make
- Review the length against the planned instrument and settings; do not apply a catalog example to every link.
- Record to prepare
- Instrument model, wavelength and pulse settings, fiber type, length and connector end faces.
Topic-specific checks
- Provide the OTDR model, wavelength, planned pulse width and link range; check near-end event measurement conditions against the instrument manual.
- Confirm fiber type, end faces, storage format and far-end measurement setup before determining launch-fiber length.
Four-step selection check
- Define the actual interfaces and mating parts at both ends
- Record fiber type, count, channel map and polarity
- Confirm length, bend routing, breakout, jacket and environment
- Agree samples, test method, limits and data format
Evidence to request when sourcing
Request drawings, material boundaries, test methods, sample records and batch traceability that match the purchased revision. Certification marks, performance values and environmental ratings matter only when they map to a specific product revision.
This guide is a selection framework, not a substitute for equipment specifications, applicable standards or the approved project drawing.