the world’s first monolithic strain DFOS sensor designed for direct embedding into the structural member, concrete or soil

EpsilonRebar enables accurate strain and precise crack measurements over its entire length. It takes the form of composite rebar of any diameter (standard Ø 5 mm). It is designed for direct embedding into the newly-designed structural members (concrete or soil) or to be installed within existing structures (e.g. inside grooves in concrete or on the surface of pipelines). Thanks to its high stiffness and tensile strength, EpsilonRebar could be used as a bar with a double function: measuring and reinforcing. Resistance to mechanical loads and environmental conditions makes EpsilonRebar ideal for in-situ applications within construction sites or existing infrastructure.


  • STRAIN & CRACK MEASUREMENT ALONG THE ENTIRE LENGTH of the sensor, optionally also temperature changes
  • EXCELLENT INTEGRATION with the monitored structure (ribbed external surface)
  • SHARP and PRECISE view of any local phenomena, especially cracks in concrete
  • EASY INSTALLATION – lightweight sensor, ready to use when unrolled from the drum
  • RESISTANT TO ENVIRONMENTAL CONDITIONS, including electromagnetic fields and lightning strikes


  • STRUCTURAL HEALTH MONITORING of engineering structures
  • GEOTECHNICAL AND HYDROTECHNICAL ENGINEERING (e.g. slurry and retaining walls, piles, concrete columns, dams, embankments)
  • LINE STRUCTURES: roads and bridges, tunnels, railway lines, pipelines and others

Application of DFOS strain Sensors for the structural health monitoring of real engineering structures allows for strain measurements over the entire length with a spatial resolution starting from 5 mm. The key thing is to use sensors that are accurate and reliable. EpsilonRebar provides new opportunities in the quantitative and qualitative assessment of strains and cracks in concrete. It allows for the precise detecting of the cracks locations and estimating their actual width during changing environmental conditions over the long term.

Technical specifications:

Strain measurement resolution1,0 µɛ
Strain measurement range± 2%
Elastic modulus50 GPa
Operating temperature-20 to +100°C
Sensor diameterØ 5-20 mm (standard Ø 5 mm)
Sensor weight45 kg/km (for Ø 5 mm)
Sensor materialGFRP (glass fiber + epoxide)
Scattering usedRayleigh, Brillouin or Raman
Method of deliverycoils or straight sections
Sensor lengthany length made to order