The SmartSonic interrogator is an interferometric instrument able to detect at acoustic frequencies the small changes in the lengths of fibre between selected pairs of sensors on a fibre Bragg grating (FBG) array. The high bandwidth and low noise floor of this measurement is such that the addition of a remote SmartSonic interrogator turns a FBG array into a string of sensitive optical microphones.

Unlike conventional distributed acoustic sensing (DAS), where the signal is modulated by very low intensity Rayleigh back scattered light, the SmartSonic interrogator sets up a series of virtual fabry-perot cavities between selected FBGs and then tracks the minute changes to these cavity lengths using an interferometer and advanced data processing. In effect, a quasi-distributed acoustic sensing, or Q-DAS, monitoring system, is established. The unique optical and data processing architecture of a SmartSonic Q-DAS system has certain key advantages over alternative technologies:

  • the process of amplitude normalisation allows measurement from very remote sensors with highly attenuated connection to the instrument;
  • low noise floor allows discrimination of features invisible to DAS
  • precise knowledge of the sensing location allows for speed of sound measurements;
  • the low optical power employed makes ATEX certification straightforward;
  • the use of COTS telecoms components makes for a low cost interrogator

SmartSonic is a collaborative development between Smart Fibres (UK) and Optics 11 (NL).

  • Measure in between FBGs
  • Retrofillable to existing FBG systems
  • Broad bandwidth / low noise floor
  • Tolerant of high optical attenuation
  • Dense multiplexing capability
  • Precise spatial resolution
  • No noise from unwanted zones
  • Highly remote measurement
  • All optical sensing with Zero EMI
  • Low cost systems

Related FAQs

FAQ. What is the warranty period for Smart Fibres equipment?

All of our fibre optic sensors come with a standard one year warranty. This warranty can be increased on a year by year basis. Extended warranty is available at the time of initial purchase on request.