Traction Watcher One, TWO, is a fixed slip friction measuring instrument mounted on a vehicle for measurements on roads and airports. For road use the TWO is mounted so the measuring wheels are lined up with the left wheels of the vehicle, while for airports the wheels are towards the center. The TWO may also be mounted on a trailer.
In transport position the TWO is lifted from the ground. The unit is lowered into measuring mode automatically when a measurement is initiated. The entire process, lifting, lowering – including ground force control, is managed by the TWO computer software. The operator simply only press START or STOP button.
The TWO measure friction reliably at speed range from 2-110 km/h (1.2-70mph). This makes the product also feasible for walkways and bicycle lanes.