Too much or too little radius can cause Fiber Closure or inadequate physical contact for optimal signal transfer. 5 Flat - 0mm radius 5-12mm radius Apex offset, fiber undercut/protrusion, and radius of curvature are the main ingredients that work in concert to deliver good IL and RL performance.
Processes that drift out of this geometry range can still yield acceptable IL/RL, but sensitive traffic will be affected (such as video) and long term performance of the connector will be compromised.
Your vendor should be able to provide these geometry test reports with onhand interferometer testing. While you may not require this data for each and every connector, you should require that random testing is being performed to ensure the process is capable and not drifting out of spec. "Garage shops" will not be able to deliver this test data on demand.
Your test reports should account for each connector independently and not a total report that summarizes both ends.
Currently, there is not an industry standard for this topic. To be sure, end-face and cleanliness has a direct impact on the performance of the connector. Several organizations (most notably, NEMI) have studied the impact of end-face defects and cleanliness.
The influence of the contamination/scratches becomes more evident if they are located in the core/cladding areas. Particle contamination can cause a significant increase in IL (up to 10 times) and decrease in RL (up to 3 times). As a passive component, Greentelftth Fiber Closure can provide a great protection for fiber splicing point. It includes aerially assembling, pipeline assembling and buried underground three types. Fiber Closure: http://www.greentelftth.com/product/fiber-optical-splice-closure/