LIOS EN.SURE Long Range Power Cable Monitoring System

With even better temperature resolution at distances longer than 20 km and as fast detection as our regular EN.SURE system the EN.SURE long range system covers ranges all the way up to 70 km. Perfect for long distances or large structures - but without compromising on the accuracy of data.

Protection of assets such as power cable infrastructure is of utmost importance in order for today’s power grids to operate at highest possible level safely. The LIOS EN.SURE long range distributed temperature sensing system provides continuous temperature monitoring and hotspot detection while delivering data in a non-stop stream to operators. And all this at a distance up to 70 km per measurement channel.

NKT Photonics is the market leader in distributed temperature sensing and with our large experience and willingness to adapt each project to the desired goal we provide intuitive, customized, and reliable solutions that you can trust. With LIOS EN.SURE the reliability that is the backbone of our business has not been compromised and performance specifications are delivered the same easy way as with the shorter ranged EN.SURE system.


  • 70 km range
  • Superior hotspot detection along the whole sensor cable
  • Flexible and direct connection to management systems such as SCADA (link)
  • Up to 16 individual channels enabling one unit to cover complex infrastructure
  • Temperature resolution better than 1 °C
  • Maintenance free and simplified outdoor installation capability
  • Real time Thermal Rating (RRTR) software calculation engines based on IEC, AEIC, and IEEE standards


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Distance ranges of EN.SURE DTS Models

LIOS EN.SURE - 300, -400, -500, -600, -700 30 km, 40 km, 50 km, 60 km, 70 km

Optical data

Optical Channels (internal) 1, 2, 3, 4, 6, 8, 9, 12 or 16
Fiber Configuration No loop or termination required
Optical Connector (s) E2000 / APC
Fiber types Single-mode 9/125, e.g. ITU-T G.652, G.655 or G.657
Laser Classification Class 1M (IEC60825-1) eye-safe wavelenght

Measurement Performance*

Sampling Interval 0.25, 0.5 or 1 m
Spatial Resolution (availability depending on distance) 1, 2, 3 or 5 m
Temperature Resolution, minimum <0.1 °C
Temperature Resolution @ 10 dB Optical Loss <1°C
Temperature Accuracy 2°C**
Measurement Time 1 to 20 min

*Measurement performance parameters are interdependent
**After calibration on a loose fiber without strain

Data Storage/Communication/Interfaces

Internal SSD Storage 8, 16, 32 or 64 GB
Communication Interfaces 2x Ethernet TCP/IP, USB, (optional: WLAN, GSM)
Communication Protocols (options) XML, MODBUS, DNP3, IEC60870, IEC 61850
Programable Inputs/Outputs 4/10
Fixed Outputs Collective fault and alarm
I/O Board (optional)* 4 inputs/12 outputs
Analogue Sensors Interface Board (optional)* 4x Pt100, 2x 0(4)-20 mA and 2x 0-10 V
Analogue Outputs (optional external module) 4 - 20 mA

*2 optional boards can be installed

Mechanical Data

Rack Space 19-inch rack, 3 height units
Dimensions HxWxD 13.3 x 43.9 x 40.3
Weight 15 kg

Environmental Conditions

Power Consumption, max. (DC/AC options) 40 W / 45 W
Operating Voltage (DC-1 option) 12 ... 24 V DC (-15%/+10%)
Operating Voltage (DC-2 option) 24 ...  48 V DC (-15%/+10%)
Mains Voltage (AC option) 100 ... 240 V Ac 50 ... 60 Hz / 110 ... 220 V DC (-15%/+10%)

Conformity to Standards

Electrical Safety IEC/UL 61010-1, LV directive 2014/35/EC, CAN/CSA-C22.2
EMC* EN61326-1, EN61000-62,3 -4-2, 3, 5, 5, 6, 8, 11, -3-2, 3, FCC 47 CFR Ch. 1 part 15
Hazardous Substances, waste RoHS directive 2011/657EC, WEE directive 2002/96/EC
Environmental Testing* IEC 60068-2-6, 14, 27, 30
Environmental Safety (IEC 61508)* Hardware design compliant to Safety Integrity Level SIL2
Explosion Safety (option)* EX II (1) [Ex op is T4 GA] IIC/II 81) [Ex op is Da] IIIC/I (m1) [Ex op is MA]

*Qualification in process