Optical fibre water detector

The fibre optic water detectors identify and pinpoint water or chemical mixture entry in closed junction boxes or collecting tanks. The water detector works on the basis of the bending sensitivity of singlemode fibres in acc. with ITU-T G.652 or ITU T G.657. On contact with the target medium, the water detector causes bending in the selected singlemode monitoring fibre, causing measurable attenuation increase. To keep a check on the route, a comparative measurement should be made regularly (at least once a month) and checked for deviation against the reference measurement made when the route was approved. Attenuation increases (e.g. due to an activated detector) and other factors can be identified in this way. If an activated water detector is identified, the fault can be rectified, which will lower the attenuation increase. In networks with bend-insensitive singlemode fibres in acc. with ITU-T G.652.D and ITU-T G.657.A, activated fibres can be used for monitoring purposes.

Monitoring options:

The optical fiber water detector can be
used for the following monitoring tasks:


Analyte: water mixtures pH 2-14

  • from a relative humidity of > 70 %
  • water leaks of pH 2-14 for buildings, (computer systems), welding points on insulated protective ducts,  tunnels, pits. Suitable for EX-zones.
  • "Compressed sponge" sensing element


Analyte: > 10% acid-/ water mixtures

  • In buildings, collecting tanks etc.
  • The monitoring (transmission) paths used are compatible with standard telecommunication facilities (LAN & WAN)
  • Monitoring distances from a few metres up to 80 km
  • No electrical connections (no amplifiers)
  • Suitable for security areas, or areas with hazardous substances or danger of explosion
  • Suitable for corrosive or electromagnetic environments