New Product Alert – VICONOX NO2, NO, CO and Visibility Monitor

Thu 27 Mar 2014

Tunnel Sensors proudly launches its newest tunnel monitor, the VICONOX Combined NO2, NO, CO and Visibility Monitor.

More and more modern vehicles emit less and less CO so there is a growing international requirement to measure the level of both CO and NO/NO2 in road tunnels.  The VICONOX provides an elegant solution to these requirements by measuring NO2, NO, CO, visibility and temperature within a single sensor.

Designed specifically for use in tunnels, the VICONOX tunnel monitor uses a combination of differential optical absorption and infrared spectroscopy to measure nitrogen dioxide (NO2), nitric oxide (NO), carbon monoxide (CO) and visibility in tunnel atmospheres. The VICONOX measures the gas concentration directly in situ in the tunnel, exactly where road users are exposed to them.

The VICONOX is able to measure up to five (5) parameters simultaneously (including temperature) or combinations thereof; with five different model options available to meet customer requirements. This not only minimises capital cost but also minimises the requirements for cabling, installation and start-up. The VICONOX also measures temperature and humidity so all measurements are compensated for both factors to ensure stable readings across all conditions.

For further information, please contact our sales team.

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We have developed a good working relationship and received excellent service throughout the installation and commissioning period. Since then, the instruments have performed very well.

Clive Dyche A.C.M.I.
Medway Tunnels, UK

Tunnel Sensors


The LUMIOS MkIII measures the level luminance, or brightness, at tunnel portals to ensure that the visual perception of drivers is maintained, both day and night.


The AIRFLOW offers a rugged, non-contact solution for the universal requirement to monitor air velocity and direction in the tunnel.


The VNOX offers a single sensor
solution for monitoring NO2
and visibility within the tunnel