how to perform a fiber acceptance test W-8LE

Acceptance testing is critical to ensure the fiber optic cable meets or exceeds manufacturer specifications.
Verifies cable integrity after multiple shipments from factory to installer, reducing risk of damage from mishandling, accidents, vandalism, or improper packaging.

Performed by Cable Distributors: Acceptance testing should be conducted by buyers or installation contractors upon receipt of the cable.
Documentation: Accurate documentation of results is essential, creating a clear paper trail from manufacturer to installer.
Request and compare this documentation with your own acceptance test results.

Package Inspection: Check for damaged or hastily repaired packaging, indicating potential mishandling.
Cable Inspection: Look for obvious signs of damage:
- Improper spooling or crossovers.
- Broken reels or damaged pellets.
- Foreign objects (rocks, wood, metal) entangled with the cable.
Example of Damage: A nail through the wooden reel into the spool cable requires immediate rejection and return to supplier.

Fields to Include:
- Fiber type and manufacturer
- Index of refraction
- Cable reel number
- General appearance
- Start and end sequential markings
Identification: Each fiber must be identified on the form using a standard fiber color code.
As tests are performed, record:
- Fiber distance (in feet or meters)
- Wavelength of testing
- Operator comments on irregularities

Primary Methods:
- BOTDR (Brillouin Optical Time Domain Reflectometry)
- Optical Loss Tests
- OTDR (Optical Time Domain Reflectometer):
  - Most popular and comprehensive method.
  - Performs precise length measurement and identifies high attenuation areas.
  - Produces hard copy records for each fiber tested.

Cable Preparation:
- Strip approximately two meters of jacketing and buffer material to expose fibers.
- Secure cable for safe access and organize fibers by color code.
Cleaning:
- Use alco pads to clean moisture repellent gel from fibers.
Connecting to OTDR:
- Fibers are connected using a pigtail and mechanical splice filled with index matching gel.
Cleave Preparation:
- Strip two inches of coating, then cleave to ensure a flat end face for optimal optical connection.

Initial Setup:
- Switch on OTDR and perform self-diagnostics.
- Ensure proper settings such as:
  - Operating wavelength (850 nm for multimode; 1310 nm for single-mode)
  - Index of refraction for accurate distance readings.
  - Appropriate pulse width and range.
Testing Procedures:
- Place reference markers accurately along the backscatter trace:
  - Start of backscatter line beyond the dead zone
  - End point just before the reflective fiber end.
- Start averaging mode to display total loss, loss per kilometer, and total distance.

Switch to real-time mode to test subsequent fibers.
Averaging mode allows for displaying backscatter trace for the next fiber, with reference markers from the first fiber remaining valid.

Optical Continuity Test:
- Low-cost method to verify light pass-through and fiber continuity.
Light Source and Power Meter Method:
- Measures attenuation; however, lacks accuracy and does not provide fiber length information.
Both methods are unsuitable for mission-critical applications but useful for short spans or low-speed systems.

Perform a final cable inspection and ensure all fibers have been tested.
Seal cable ends to prevent contamination and moisture ingress using electrical tape or heat shrinkable tubing.

Acceptance testing is integral to optical communications installation, validating cable performance specifications before installation.