Calibration and connectors: taming the troublemaker in fiber networks

One of the main causes of service interruptions in fiber-optic networks is faulty connectors. These small yet mighty optical components are the #1 headache for field crews working under time constraints. And as a known troublemaker, connectors provide an excellent example of why calibration of test tools is so critical.

Connectors are vulnerable to issues like becoming dirty or misaligned, or damaged such that they cause high insertion loss or excessive reflectance.  

Diagnosing connector failure 

When a connector fails, pinpointing and resolving the issue demands fast, accurate diagnostics, which typically requires optical time-domain reflectometers (OTDRs) to assess their status. It’s essential that OTDRs are properly calibrated to provide accurate measurements of parameters such as insertion loss, reflectance and distance.  

Testing optical links with an OTDR allows the technician to differentiate issues caused by connectors from those caused by splices and bends or even breaks elsewhere in the fiber. OTDRs are a critical device for accurate fiber characterization at the build or upgrade phase and for effective troubleshooting.  

Uncalibrated OTDRs can lead to errors such as mis-identifying the location of a failure or mis-reading reflectance levels and subsequently producing false positives meaning missing a failed connector, or a false negative by flagging a viable connector as having failed.  

OTDRs must be calibrated at the time intervals advised by the manufacturer to ensure consistent performance. With appropriate maintenance, field technicians can avoid unnecessarily replacing connectors that are still performing within acceptable limits.  

Implications of uncalibrated equipment 

Long-term consequences of skipping calibration or relying on services from uncertified test centers include: 

• false positives or false negatives in fault detection. 
• unnecessary replacement of connectors or other components. 
• extended network downtime due to misdiagnosis. 
• failure to meet client expectations for network reliability.  
• lack of compliance with industry standards.

In conclusion 

Properly calibrated test and measurement (T&M) equipment ensures accurate diagnosis and efficient resolution of connector failures. By investing in regular calibration and adhering to best practices, network operators safeguard performance, reduce operational costs, and deliver on reliability, while ensuring compliance.