Air quality measuring devices

For ventilation control and accurate nitric oxide monitoring in road tunnels

Your Benefits

  • Energy and cost savings for ventilation control due to very low zero offset and accurate measurement
  • Low operational costs because no air aspiration of ambient air and no test gases are required
  • Low maintenance requirements due to long maintenance interval (approx. 1 year)

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.


For ventilation control and accurate nitric oxide monitoring in road tunnels

The VICOTEC320 measures very small concentrations of NO2 and NO as well as the visibility and temperature in road tunnels quickly and simultaneously. And all this using industry-proven components – without test gases for zero and reference point. An automated, cyclic adjustment of zero and reference point ensures exact values. The rugged housing even withstands thorough tunnel washing operations without any impairments.

The VICOTEC320 can be optionally equipped with an electrochemical CO measurement cell. This is useful for performing the plausibility checks with CO which some tunnel standards (e.g., German RABT2006) recommend – even when NO2 is used as lead gas component.

At a glance
  • Very low detection limits for NO and NO2
  • Automatic function monitoring and self-adjustment
  • Very rugged design in stainless steel
  • Automatic beam alignment between sender/receiver unit and reflector


Spare parts


Service & Support

Technical overview

  • VICOTEC320 system

    VICOTEC320 system

    Measured valuesVisibility (K-value), NO, NO2, NOx, CO, temperature
    Measurement principlesDifferential optical absorption spectroscopy (DOAS), transmittance measurement, electrochemical cell, Resistance thermometer
    Measuring distance
    10 m
    Measuring ranges
    K-value0 ... 15 km⁻¹ / 0 ... 200 km⁻¹
    NO0 ... 20 ppm / 0 ... 45 ppm
    NO20 ... 1 ppm / 0 ... 5 ppm
    CO0 ... 100 ppm / 0 ... 300 ppm
    Temperature–25 ... +55 °C / –25 ... +75 °C
    Response time (t90)
    Visibility (K-value)5 s ... 360 s
    Adjustable (45 s pre-configured)
    NO, NO25 s ... 360 s
    Adjustable (45 s pre-configured)
    CO≤ 60 s
    NO± 0.48 ppm
    NO2± 0.035 ppm
    Detection limit
    Visibility (K-value)0.03 km⁻¹
    NO0.002 ppm
    NO20.007 ppm
    Visibility (K-value)0.017 km⁻¹
    NO0.031 ppm
    NO20.007 ppm
    Ambient temperature
    –20 °C ... +55 °C
    CO sensor–10 °C ... +40 °C
    Storage temperature
    –25 °C ... +75 °C
    CO sensor0 °C ... +20 °C
    Ambient pressure
    700 hPa ... 1,200 hPa
    Ambient humidity
    10 % ... 95 %
    Relative humidity; non-condensing

    ASTRA "Guideline - Ventilation of Road Tunnels" (2008)

    RABT 2006

    RVS 09.02.22

    Electrical safetyCE
    Enclosure rating
    Analog outputs6 outputs:
    0 ... 20 mA
    Depending on device version
    Digital outputs4 relay contacts:
    Depending on device version
    Digital inputs4 potential-free contacts
    I/O extensionsOptical fiber connection optional
    FunctionConnection to SOPAS ET software or OPC server
    Type of fieldbus integrationTCP
    CAN bus
    FunctionFor connection of a SCU control unit
    OperationVia software SOPAS ET
    Dimensions (W x H x D)
    Sender/receiver unit718 mm x 470 mm x 310 mm (for details see dimensional drawings)
    Reflector unit617 mm x 278 mm x 245 mm (for details see dimensional drawings)
    Connection unit450 mm x 254 mm x 148 mm (for details see dimensional drawings)
    Sender/receiver unit20 kg
    Reflector unit9 kg
    Connection unit8 kg
    MaterialStainless steel 1.4571, powder-coated
    Power supply
    Voltage115 V AC, ± 10 %
    230 V AC, ± 10 %
    Frequency50 Hz / 60 Hz
    Power consumption≤ 200 VA
    Test functions

    Automatic check cycle for zero and span point

    Contamination check

    Manual linearity check

    OptionsCO sensor
All technical data can be found accompanying the individual product