PLEXUS Interrogator Unit

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OptaSense Plexus IU

Delivering Long-Range, High-Sensitivity Quantitative Data

The PLEXUS Interrogator Unit delivers long-range quantitative data performance with high-fidelity and sensitivity, providing the ultimate in interrogator systems for all manner of Distributed Fiber Optic Sensing applications.

Bringing Quantitative Data to Life

The PLEXUS interrogator unit opens up a new realm of possibilities for those customers with a need for accurate, high-quality data streams from their linear monitoring systems. In the past, those jobs that required quantitative data were limited to a range of 10 km, making fiber-optic sensing too expensive and inefficient for longer-range applications.

The PLEXUS interrogator unit changes all that by breaking through the 10 km barrier. Only the PLEXUS interrogator unit has the ability to provide high-quality data, with increased sensitivity, out to a range of 50 km, five times that of standard interrogator units. And unlike other systems in the market, the PLEXUS interrogator unit has delivered proven results on a standard single-mode fiber optic cable, eliminating the need for costly specialty cables.

Quantitative data has always been at the heart of our downhole applications. Now the benefits of a quantitative approach has been brought to our industry-leading long-range applications. As a stand-alone device, or integrated into our software suites, the PLEXUS interrogator unit allows a wealth of new information routes that require better data quality and improved signal to noise ratio at longer ranges.

Applications for the PLEXUS interrogator unit include:

  • Long baseline seismology and tsunami monitoring
  • Rail and road applications
  • Static strain monitoring
  • Pipeline integrity monitoring
  • Subsea cable monitoring
  • Fenceless border surveillance
  • Advanced research applications

The Benefits of a Quantitative Approach

Our Intensity-only applications have delivered a huge benefit to our clients over the last decade with thousands of miles of deployments. The PLEXUS interrogator unit is prepared for the next revolution, opening up a wide range of extended capability and performance:

  • Fundamental output from interferometer in specific, absolute units
  • Reveal Strain behaviour at the same as acoustic behaviour allowing multiple applications to be delivered in parallel – e.g. Pipeline Strain at the same time as TPI
  • Ability to process data as an array: beam forming / SNR via signal integration
  • Linear response to signals
  • True undistorted audio response
  • Proven on standard single-mode fiber

For our clients, this means both a superior performance on existing algorithms (lower NAR, higher Pd, improved sensitivity) and the opportunity to open up exciting new application spaces (such as strain monitoring, seismic tensor analysis, electromagnetic monitoring, beam-forming etc.)

Superior Performance

At long ranges, the PLEXUS interrogator unit is our highest-performing device with a significant sensitivity gain over our baseline 3rd generation and 4th generation devices. The result of four years of technical development where a wholly new interrogation scheme allows us to move away from the frequency-limited dual-pulse approach. The PLEXUS interrogator unit serve as a basis from which we will build upon further in the future.

  • Low phase noise, specially-developed RIO laser at the heart of the device
  • Wider frequency range at all ranges - delivering 50% of ping rate - full Nyquist
  • Up to 50km of quantitative data

System Highlights

The PLEXUS interrogator unit provides real-time delivery of quantitative phase and amplitude information over all distances. Other features include:

  • +15dB noise floor improvement over equivalent mode 3rd generation: -61dB Rad/Hz (at start of 40km fibre)
  • Easily adjustable gauge lengths which can be optimized for deployed cable length
  • 1m output channel pitch
  • 1/2 ping rate frequency output
  • GPS time synchronization
  • Flat frequency response including down to DC (0 Hz)
  • Up to 50km data output, delivering 50,000 channels at 2 kHz ping rate acquired in real time - 100% of data can be written to SSD or RAID0 HDD
  • Designed to maximally exploit the benefits of the latest engineered fibers and cables
  • High-sensitivity and low noise floor for strain and temperature monitoring (mK/µε)
  • Range of ping rates and acquisition options from 2km up to 200km-long cables gauge lengths from 2m to 35m
  • Eye Safe Class 1 laser operations

Ready for unmatched quantitative data?

Did you know

In addition to acquiring DAS, OptaSense provides operators the ability to visualize and interpret their data, in real time.

The OptaSense DxS browser software suite provides an in depth analysis of acquired DAS data by applying processing algorithms, integrating large sets of distributed data, filtering critical data and enabling advanced workflows. The software suite allows users to easily integrate large distributed data sets into workflows, including 3D depth, time and measurement data, while managing quality control, analysis and interpretation.

Visualization Software

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