With DE.TECT temperatures are recorded as a continuous profile along the entire sensor cable compared to a conventional setup using single point-type sensors.

The benefit of achieving highly accurate temperatures over great distances at short measuring times is combined with the ease in installation and data acquisition.

Technical Highlights :

  • Linear heat detector for quick fire detection and precise localization of the fire source
  • Alarm and pre-alarm for each zone
  • Selectable alarm and pre-alarm criteria
  • High spatial resolution – down to 0.25 m
  • Signal processing based on OFDR-Technology (Optical Frequency Domain Reflectometry)
  • Available with 1, 2 and 4 channels
  • 1000 free programmable zones for each channel
  • Information regarding magnitude and the direction of the fire spread
  • Redundant sensor system applicable
  • Suitable for wind speeds of up to 10 m/s
  • Laser product class 1M according DIN EN 60825-1: 2007



LIOS EN.SURE is based on state of the art distributed temperature sensing (DTS) monitoring systems customised for the electrical T&D industry. One single EN.SURE evaluation unit provides fast temperature sensing profiles with high spatial resolution along the optical fibres route with monitoring ranges up to 40km per channel.

The LIOS‘ DTS technology has been successfully proven in critical applications like fire detection in road and rail tunnels and special hazard buildings, power cable and aerial transmission line monitoring, in oil & gas exploration for permanent downhole monitoring and for industrial induction furnaces surveillance, where these systems have been equipped in world-wide projects with more than 2500 permanent installations.

Most of these applications are safety relevant and require high reliability and uptime of the sensor system. The EN.SURE DTS product series was carefully designed and thoroughly tested targeting reliable performance and smooth operation in industrial environments. Excellent Mean-time-between-failures (MTBF) of 28 years was reached based on the latest statistical field analysis of the current DTS product series.

Technical Highlights

  • Highly reliable industrial design with key components approved by the telecom industry (tested according to Telecordia standard GR-468, with medium lifetime >25 years)
  • Signal processing based on patented Raman OFDR-Technology (Optical Frequency Domain Reflectometry)
  • Superior hotspot detection along the whole sensor cable length even at most remote distances based on the invariant OFDR spatial resolution
  • Flexible and direct connection to management systems such as SCADA and real time thermal rating (RTTR) software calculation engines based on IEC, AEIC and IEEE standards
  • Up to 16 internal fibre optic channels – 1 EN.SURE DTS unit can cover the most complex power cable circuits
  • Temperature resolution better than 1 °C
  • Laser product class 1M according to DIN EN 60825-1: 2007
  • Maintenance free and simplified outdoor installation capability through higher allowed operating temperature range and fan-free DTS unit design
  • Impressive track record with more than 2500 permanent units installed worldwide


LIOS Technology provides the appropriate sensor cable for every application.

One vital component is a tube that accommodates 2 optical fibres. The coatings of the optical fibre can be tailored to optimally suit the required resistance to temperature conditions and mechanical impacts. The wall thickness of the tube sheathing, the material used and additional protective measures as stranded wires or coatings allow for an optimized design.

Versions with an additional stranded wire layer upon the tube are available for fast temperature detection or if stricter requirements apply with regards to tensile strength and mechanical robustness. For applications with a high amount of electromagnetic disturbances like rail tunnels or power supply line tunnels LIOS offers a metal-free cable to minimize the risk of induced voltages. No electronic components are needed along the cable. The sensor is completely passive over its entire detection range.

The DE.TECT fibre optic linear heat detection can therefore be carried out in areas where high safety risks exist, e.g. in areas with a risk of explosion.