The High Sierra Electronics RWIS Passive Runway/Highway Surface Sensor Station is an Environmental Sensor Station (ESS) that is NTCIP (National Transportation Communications for ITS Protocol) compliant, which simplifies integration with other field devices in an Intelligent Transportation Systems (ITS) Network.
Real-time anti-icing knowledge of the pavement surface state is necessary for making an informed decision on treatment and for message sign activation. The RWIS Passive Runway/Highway Surface Sensor Station – Model 5721-05 is an NTCIP compliant remote processing system for monitoring the actual road surface environment. The Passive Runway/Highway Surface Sensor Station is well suited for roadways, ice-prone bridges, elevated roadways (including entryways, parking garage ramps or loading docks), and other commercial applications.
The primary use of the Passive Runway/Highway Surface Sensor Station is for ice warning. The Passive Runway/Highway Surface Sensor Station consists of a Signal Processing Module, a Road Surface Sensor, an optional Deep Road Temperature Sensor, and Signal Conditioning Modules. The Passive Runway/Highway Surface Sensor Station’s processor derives the state of the roadway surface by observing temperature and moisture phase change on the surface. Deep Road Temperature is useful in predicting icing where roadway mass is affected (i.e. overpasses and elevated roadways). It can also serve as a guide as to whether de-icing chemicals remain on the surface, or if reapplication is necessary.
Conditioned pavement sensor signals are applied to the Passive Runway/Highway Surface Sensor Station’s Signal Processor/Controller board, which samples conditions and determines the roadway state (Dry, Wet or IceWatch). This surface condition as well as surface temperature, deep pavement temperature, and surface wetness are populated into the appropriate NTCIP 1204 (ESS) Object Identifiers (OIDs) and are transmitted by the Passive Runway/Highway Surface Sensor Station when the device address is polled.
The surface sensor element, Model 5721-51, is molded in a resilient epoxy compound with thermal properties that closely match the roadway surface. It works on thermally passive principles: no artificial heating or cooling is used that may alter the measured environment. The maintenance free design features corrosive- resistant electrodes to derive the presence of moisture on the roadway surface.