Skip to main content

Biral’s RWS-30 weathers poor tunnel visibility

Meteorological equipment specialist Biral has launched the RWS-30 road tunnel weather sensor for accurate and reliable visibility measurements. The sensor is easily integrated with systems in road and tunnel applications and monitors obstruction to vision caused by fog, smoke and exhaust fumes. The company says that the forward scatter measurement principle provides a compact design with measurements that are both accurate and reliable in all weather conditions. Sensor features include window contaminatio
October 18, 2018 Read time: 2 mins
Going underground with Biral’s RWS-30 weather sensor
Meteorological equipment specialist 8558 Biral has launched the RWS-30 road tunnel weather sensor for accurate and reliable visibility measurements.


The sensor is easily integrated with systems in road and tunnel applications and monitors obstruction to vision caused by fog, smoke and exhaust fumes.

The company says that the forward scatter measurement principle provides a compact design with measurements that are both accurate and reliable in all weather conditions. Sensor features include window contamination monitoring with automatic measurement adjustment to allow maintenance only when needed.

The RWS-30 has a measurement range of 200m - 99.99km - with a resolution of 1m - making it very sensitive for both air quality and fire detection. To ease integration, the sensor has the ability to report EXCO or MOR as a 4-20mA current output as favoured in tunnel systems.

Alternatively, either the serial data output or optional relays can be used.

The measurement of visibility by forward scatter as used by the RWS-30 is now widely accepted and is seen as having significant advantages over more traditional techniques such as the use of backscatter sensors or transmissometers.

Backscatter sensors share the RWS-30's advantage of being compact; however, the backscatter signal is strongly dependent on the type of obstruction to vision. This results in poor accuracy and limited upper range.

More importantly, due to the problem of reflections, backscatter sensors require a large open area in front of the sensor to operate correctly.

For more information on companies in this article

Related Content

  • Vaisala PWD10 visibility sensors for Arizona
    December 19, 2022
    Vaisala provided its PWD10 visibility sensors and its Road Weather Station RWS200 system to make driving safer on a dangerously dusty and wind-blown highway.
  • SICK’s LMS 1000 and RMS 1000 sensors deliver the goods
    January 7, 2019
    SICK says that it’s recently launched LMS1000 and MRS1000 infrared LiDAR sensors deliver more accurate and reliable distance sensing and measurement, especially in difficult conditions. The robust, compact sensors weigh just 1.2kg and come with rotatable connectors for easy mounting on gantries. Heavy rain, mist, dust or snow can lead to false signals, explained Neil Sandhu, SICK’s national product manager for imaging, measurement, ranging and systems. The addition of SICK’s triple-echo HDDM+ - High Defini
  • Accurate weather detection in tough environments
    July 30, 2019
    Biral’s VPF-730 unit is designed for effective weather detection in areas of maximum corrosion risk. It is suitable for installation on coastal highways or on bridges crossing tidal estuaries for example. The firm claims that the unit provides accurate visibility and present weather measurement and suits use in many tough installations due to its efficiency, reliability and performance. The sensor is a compact and robust package with an exceptionally long service life of 15 years or more. It suits use i
  • Warning for lightning strikes
    July 3, 2019
    Meteorological specialist, Biral, is introducing its new BTD-200 Lightning Warning System. This system is said to be a complete detection and warning package, which has been developed from the Biral range of professional aviation grade lightning detection systems. It can detect reliably the local presence of all forms of lightning out to a range of 35km from the sensor. Designed to be installed and set up by non-technical staff, it comes with a power supply and the essential PC application ‘Lightnin