Meteorological equipment specialist Biral has launched a new road weather sensor, the RWS-20, designed for the harsh roadside environment. The RWS-20 is based on the existing SWS range of visibility sensors, and has been designed to allow easy integration with any road weather information system (RWIS). The new design is a compact forward-scatter measurement principle and remains accurate in all weather conditions, ensuring that local light sources, headlights or flashing signs do not affect its operation or reliability. With a measurement range of 10m to 7.5km, the RWS-20 is intended for road applications where fog, rain, spray and snow can create dangerous driving conditions. The optical windows and sensor hoods contain heating for use in harsh weather conditions. Both optical windows have systems for lens contamination monitoring, meaning that the visibility output is constantly compensated to maintain accuracy while reducing routine maintenance duties. The new sensor has a serial data output of RS232, RS422 or RS485, and provides analogue voltage visibility outputs (0-10V) or the extinction coefficient (EXCO). The RWS-20 also features optional relays that can directly connect to roadside signage and other control systems.