Fiber-based Current Monitoring
Fiber-based Current Monitoring

Fiber-based Current Monitoring of AC power cables

AP Sensing’s Fiber-based Current Monitoring (FbCM) expands the functionality of our Distributed Acoustic Sensing (DAS) technology with the option of electrical condition monitoring. Customers or interested parties who consider AP Sensing's DAS technology for cable fault location and intrusion detection can now use our FbCM to monitor critical currents in the power cable - very easily and in a highly integrated manner. Sheath currents of AC power cables are indicators for the functionality of bonding, insulation failures, link box flooding, unwanted ground contacts and sheath damages resulting from Third Party Intrusions (TPI). AP Sensing’s FbCM can detect all those issues in real-time.


AP Sensing’s FbCM solution enables precise permanent monitoring of three-phase sheath currents at remote locations by using a DAS interrogator and remote FbCM sensors. Multiple FbCM sensors at different locations can be interrogated by a single DAS, all connected by the same optical fiber over distances up to 50 km. The passive, robust and compact FbCM sensors can be installed in manholes or pits and do not require any power supply. AP Sensing’s FbCM solution is designed to upgrade new as well as existing DAS projects.

Benefits of FbCM

  • Permanent monitoring detects issues in real-time, such as:
    • Bonding issues
    • Cable insulation failures
    • Link box flooding
    • Unwanted ground contacts
    • Sheath damages caused by Intrusion Events (TPI)
  • Easy to integrate into any DAS project – no special interrogator required
  • No extra optical fiber required – the FbCM sensors use the DAS fiber
  • Multiple locations can be monitored by a single interrogator over distances up to 50 km
  • Combination of acoustic (DAS) and electrical TPI detection
  • Software-adjustable alarm thresholds
  • Transmission of current data and alarms to SCADA in real-time
  • Easy to retrofit, no need to disconnect cable
  • Purely passive – no power supply needed
  • Robust and compact design for installation at remote locations like manholes or pits


Patent pending. This product is not available in the USA and the UK.


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