LIOS PRE.VENT Long Range Industrial Temperature Monitoring System

LIOS PRE.VENT Long Range provides flexible and precise solutions for industrial temperature monitoring, even at very large sites or over longer distances. Utilizing the most advanced DTS technology specifically made for industrialized surroundings, every installation provides safe, fast and straight-forward monitoring of furnaces, gasifiers, and a large array of plants, vessels, and infrastructure. No challenge is too large for this long range edition of the LIOS. PRE.VENT.

With all the benefits of the LIOS PRE.VENT, but with an even longer measuring range, the LIOS PRE.VENT Long Range offers users a unique chance to monitor very large structures with just one installation. The solutions provides highly reliable and exact dataeven in industrial environments while providing robustness, scalability, and an option to have up to 16 individual channels enabling the coverage of complex infrastructure. Even on large and complex installations the LIOS PRE.VENT Long Range still provides a cost-effective and yet fully automated data analysis with very precise and accurate temperature mapping.

Using only one single optical fiber, our DTS system covers thousands of measuring points along the sensor cable making the DTS technology far more efficient in installation and maintenance cost compared to other sensor technologies.  Furthermore the fiber can withstand very high temperatures, mechanical and environmental exposures and can therefore be used for a very large variety of applications where extreme heat is a challenge: for instance in induction furnaces or chemical reactors.

At NKT Photonics we are strong in design engineering and turn complex and customized solutions with different cable designs into simple turn-key solutions delivering reliable cost-effective temperature monitoring solutions.


  • Measurement range -170°C to +450°C
  • ATEX/IECEx certification
  • Operating temperature -10°C to +60°C
  • Up to 16 channels
  • 70 km range per measurement channel

LIOS PRE.VENT covers a broad range of industrial applications offering operational safety, real-time control and lifecycle optimization of assets like reactors, gasifiers, LNG tanks, containments and pipelines, as well as ecological engineering projects.

Contact us now


LIOS PRE.VENT -300, -400, -500, -600, -700 30 km, 40 km, 50 km, 60 km, 70 km

Data Storage / Communication / Interfaces

I/O board (optional*) 4 inputs / 12 outputs
Analogue sensors interface board (optional*) 4x Pt100, 2x 0(4)-20mA and 2x 0-10V

* 2 optional boards can be installed in total

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 wavelength

Measurement Performance*

Sampling Interval 0.25, 0.5 or 1 m
Spatial resolution 1, 2, 3 or 5 m
Temperature resolution, minimum < 0.1°C
Temperature resolution @ 10dB 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, IEC61850
Programmable inputs / outputs 4 / 10
Fixed outputs Collective fault and alarm
Analogue outputs (optional external module) 4 - 20mA

Mechanical Data

Rack space 19-inch rack, 3 height units
Dimensions (H x W x D) 13.3 x 43.9 x 40.3 cm
Weight 15 kg

Electrical Data

Power consumption, max. (DC / AC options) 40W / 45W
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%)

Environmental Conditions

Storage temperature -40°C to +85°C
Operating temperature -10°C to +60°C
Humidity (relative) ≤95 % (non-condensing)
Protection class (IEC 60529) IP51

Conformity to Standards

Electrical safety IEC/UL 61010-1, LV directive 2014/35/EC, CAN/CSA-C22.2
EMC* EN61326-1, EN61000-6-2,3,-4-2,3,4,5,6,8,11,-3-2,3, FCC 47 CFR Ch.1 Part15
Hazardous substances, waste RoHS directive 2011/65/EC, WEEE directive 2002/96/EC
Environmental testing* IEC 60068-2-6,14,27,30
Functional safety (IEC61508)* Hardware design compliant to Safety Integrity Level SIL2
Explosion safety (option)* EX II (1) G [Ex op is T4 Ga] IIC / II (1) D [Ex op is Da] IIIC / I (M1) [Ex op is Ma]

* Qualification in process