Smoke detectors

Early and reliable fire detection in tunnels

Your Benefits

  • Perfect addition to temperature cables thanks to earlier and faster detection
  • High levels of reliability and operational safety
  • No need for protective measures during tunnel cleaning
  • Immune to gantry fog
  • Flexible connection options, easy to extend and integrate into existing networks
  • K value can be easily verified with a checking tool
  • Low level of effort due to simple mounting and quick commissioning
  • Alarm signal with adjustable limit value

The exact device specifications and performance data of the product may deviate from the information provided here, and depend on the application in which the product is being used and the relevant customer specifications.


Early and reliable fire detection in tunnels

The VISIC50SF smoke detector offers high-speed measurement to ensure fast and reliable smoke detection when tunnel fires occur. The VISIC50SF is very easy to mount, operate, and maintain. There is no need for alignment or parameter setting – measuring starts right away. With its IP6K9K enclosure rating, not only is the VISIC50SF able to withstand the harsh ambient conditions inside the tunnel, but also tunnel washing operations without any problems. During the design phase, particular importance was placed on ensuring reliable operation and long maintenance intervals. That is why there are no moving parts. There is an optional version available with heating for fog evaporation. This allows the VISIC50SF to effortlessly meet your desired requirements, making it the perfect solution for the fast and reliable detection of fires.

At a glance
  • Visibility (K value) measured according to the scattered light measurement principle
  • Highly available – no moving parts
  • Quick and reliable smoke detection
  • Software developed in accordance with EN 61508 (SIL1)
  • Low faulty alarm rate
  • IP 6K9K enclosure rating thanks to a rugged stainless-steel housing
  • Fog evaporation through integrated heating element (optional)


Spare parts


Service & Support

Technical overview

  • VISIC50SF system

    VISIC50SF system

    Measured valuesVisibility (K-value)
    Measurement principlesScattered light forward
    Measuring ranges
    Visibility (K-value)0 ... 150 km⁻¹
    Temperature measurement (option)–30 ... +70 °C
    Response time (t90)
    ≤ 5 s
    Visibility (K-value)1 km⁻¹
    1 %: of measuring range full scale
    Ambient temperature
    –20 °C ... +55 °C
    Storage temperature
    Measuring device–30 °C ... +85 °C
    Ambient pressure
    860 hPa ... 1,080 hPa
    Ambient humidity
    10 % ... 100 %
    Relative humidity; non-condensing

    ASTRA "Guideline - Fire Detection in Road Tunnels" (2007)

    RABT 2006

    Electrical safetyCE
    Test functions

    Contamination monitoring of glass pane

    Drift and plausibility check

    Automatic self-test

    Functional monitoring of the optional heating


    Internal heating

    Connection unit

    TAD control unit

    Temperature sensor

  • VISIC50SF sensor unit

    VISIC50SF sensor unit

    DescriptionAnalyzer unit of the measuring system
    Electrical safetyCE
    Enclosure rating
    Analog outputs2 outputs:
    4 ... 20 mA, 500 Ω
    Electrically isolated; short-circuit proof. Outputs are preset for smoke detection and temperature.
    Digital outputs3 relay contacts:
    48 V, 0.5 A, 24 W
    Preset for failure, limit value and maintenance
    RemarkNot available when a TAD is used
    Type of fieldbus integrationRTU RS-485
    LC display, inside
    Status LEDs: “Operational”, “Maintenance required”, and “Fault”
    InputFunctional keys
    OperationVia LC-display and function keys
    Dimensions (W x H x D)
    266 mm x 159 mm x 117 mm (for details see dimensional drawings)
    2.8 kg
    MaterialStainless steel 1.4571
    MountingWall mount, vertical, wall inclination up to 45° or ceiling mount using an adapter
    Power supply
    Voltage18 V DC ... 28 V DC, ± 10 %
    VoltageOther voltages with optional connecting unit or TAD control unit
    Current consumption≤ 1 A
    Power consumptionWithout heating: ≤ 5 W
    With heating: ≤ 20 W
  • TAD control unit

    TAD control unit

    DescriptionRemote controll with integrated display and additional I/Os
    Electrical safetyCE
    Enclosure rating
    Analog outputs4 outputs (option):
    4 ... 20 mA, 500 Ω
    Electrically isolated
    Digital outputs3 outputs (option):
    125 V AC, 0.6 A / 30 V DC, 2 A
    Digital inputs1 input (option):
    30 V DC
    Dimensions (W x H x D)
    210 mm x 347 mm x 129 mm (for details see dimensional drawings)
    5 kg
    MaterialStainless steel 1.4571
    Power supply
    Voltage88 V AC ... 264 V AC, ± 10 %
    Frequency47 ... 63 Hz
    Power consumption≤ 15 VA
  • VISIC50SF connecting unit

    VISIC50SF connecting unit

    DescriptionServes for connection of power supply, data and signal cabling provided by the customer
    Electrical safetyCE
    Enclosure rating
    Dimensions (W x H x D)
    266 mm x 238 mm x 146 mm (for details see dimensional drawings)
    2.8 kg
    MaterialStainless steel 1.4571
    Power supply
    Voltage85 V AC ... 264 V AC, ± 10 %
    Frequency45 ... 65 Hz
    Current consumption≤ 0.1 A
All technical data can be found accompanying the individual product