TWO - 'Traction Watcher One'

The TWO is a robust, durable, and accurate instrument for precise and efficient pavement friction measurements. The patented design works just as well in -30 degrees snow and ice conditions as in +50 degrees tropical environment.

The TWO is made of stainless steel and high-quality Aluminum it will not rust or corrode. There is either no hydraulics that may freeze or leak or get worn.

The TWO can be mounted directly on a vehicle or pre-installed on a special trailer. Both installations are available with optional self-wetting system required for pavement maintenance purposes.

There are solutions for mounting in line with left or right vehicle wheel track – or in between.

The software is installed in a laptop located at the driver seat. It will handle measurement, display and store data. The program ensures easy operations, collects results and enables reporting of details immediately after the measurements are performed.

How it works
The unit is raised and lowered by an electric actuator that is controlled by the TWO software. In upper position the TWO is free in the air and not in contact with the surface below. This is the normal position when moving between sites.

When lowered the device is pushed to the ground at a preset force by the electric actuator. The down force is measured and automatically controlled by the software.

The 2 wheels are connected mechanically by a chain. Front wheel has about twice the down force as the rear wheel. That makes the front wheel the driving wheel and is running at the same speed as the vehicle.

The rear wheel is the measuring wheel and driven by the driving wheel via the chain, but is geared so it is rotating 17.8% slower than the driving wheel.

Friction level is recorded at 100Hz and is calculated by dividing measuring wheel down force (Fd) by the measuring wheel braking force (Fb); Friction coefficient = µ =Fd/Fb.

Details and solutions
Friction measurements made easy! We offer the following options. (see above for related images)

• TWO trailer friction tester
  Designed for easy towing with any vehicle. Trailer shown without self wetting system. Lifting and lowering as well as starting and stopping is done from the drivers seat
• TWO trailer mounting
  Easily attached to all vehicles equiped with standard trailer hook. This offers a flexibility to use several different vehicles for measuring tasks.
• Trailer with watertank
  For summer measurements we offer the trailer with watering tank mounted under the trailer hood.All in one complete unit. Easy and elegant!
• TWO center mounted
  Centermounted TWO using a standard 2” square trailer hitch. This is a very common attachment and a perfect solution for airports. We deliver the friction meter pre-assembled for this type of attachment with flexible height adjustment
• TWO in lifted position
  Ready for  transport between locations. The device is easy to attache and remove after use.
• TWO mounted on left or right hand side
  TWO mounted on the supplied bracket on the left-hand side. The couplingplate has two snap locks and en extra safety device. If you prefer to measure both wheel tracks. No problem, just mount another bracket to attache a second meter
• Summer measurements
  Nozzle for self-watering of the rear meassuring wheel to record reliable measurements on dry surfaces. Designed to leave 0,1mm -1,0mm waterfilm in front of the measurement wheel. The amount of water is automatically adjusted according to the speed of the measuring wheel
• Mounting bracket
  The supplied mounting bracket must be fitted to the vehicle’s load-bearing structure on vehicles equiped with standard tow bar. This offers both rear left-hand or right-hand side mounting of the friction meter.
• Cable connector
  Electrical connection between car and meter is made with a solid Harting connector. Tested over a long period of time. Lightweight and durable.