Red lights in front of the tunnel often means poor air quality in the tunnel. Tunnel operators try to avoid such situations with continuous monitoring of visibility in road tunnels. While the market offers many measuring devices that can perform this task, the VISIC100SF from SICK is truly in a league of its own. Because it combines scattered light with an electrochemical cell, it is the world‘s only tunnel sensor that can measure exhaust fumes as well as monitoring visibility in just one compact device.
Measuring devices should work without faults and only require infrequent maintenance, while also being user-friendly and cost-effective. With VISIC100SF all of this is contained in one compact housing. The VISIC100SF starts measuring as soon as you switch it on, because it is preset at the factory. Certain processes, such as the need to align multiple components or perform configuration are a thing of the past. And because there are no moving parts, there will be no faults caused by mechanical wear.
Ingenious combination of two measurement principles
Improvements in the catalytic converter technology used on vehicles means that pollutant concentrations in tunnels are now very low. Consequently, the main measurement for ventilation control is the level of visibility. Exhaust gas measurement is also used for monitoring purposes and electrochemical sensors are ideal for this. With its VISIC100SF sensor, SICK has managed to combine the process of measuring scattered light with the measurement principle of electrochemical cells. This forward-looking solution detects visibility, CO ans NO and is the only device in the world to offer this feature in this combination in just one compact device.
Efficient ventilation control
The VISIC100SF tunnel sensor directly monitors the tunnel atmosphere on a continuous basis and provides accurate measured values for reliable and effective ventilation control. In other words, optimum air quality can be achieved with the minimum expenditure of energy. But what about fog? Thanks to its optimized heating, the VISIC100SF is able to selectively measure just the air pollution. As a result, the ventilation can be correctly controlled even when the mouth of the tunnel is shrouded in the thickest fog.
The VISIC100SF is a technical innovation that provides extremely low operating costs thanks to its long maintenance intervals of at least a year. Tunnel cleaning can be carried out without any problems at all, because the sensor’s stainless steel housing features the IP 6K9K enclosure rating.
In terms of the measurements, it is able to ensure high operational safety, because the software is developed according to the requirements of the SIL1 safety integrity level. A checking tool is available for the purpose of monitoring the visibility measurements. This can easily be used to check real values of between K = 0 and 15 1/km.
The VISIC100SF features flexible interfaces so that it can be adapted to the local mounting conditions or easily integrated into existing networks. Electrochemical sensors can also be retrofitted with ease.
The new VISIC100SF tunnel sensor from SICK – for monitoring visibility plus CO and/or NO concentrations in road tunnels for the purpose of ventilator control, for the selective measurement of visibility when the tunnel portal is shrouded in fog – or in short: anywhere where air quality has to be measured and improved.