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zentrak Wheel Defect Detection and zentrak Weighing in Motion

Wheel Defect Detection (WDD) and Weighing in Motion (WIM) are used for diagnosis of wheel defects and vehicle weights.

Diagnosis of Wheel Defects and Vehicle Weights

Growing rail traffic worldwide requests higher safety standards and lower maintenance costs at the same time. An essential aspect is a continuous, trustworthy monitoring of wheel-rail interaction forces.

Wheels of rail vehicles are exposed to high wear and tear. This may result in geometric wheel defects. The functions WDD and WIM measure on a continuous basis every wheel of the fleet and check for any deviating force levels during normal train operation.

Besides detecting wheel defects the functions are used as a dynamic rail scale at the same time; vehicle weight and load distribution are monitored during every passage and an unbalance or overload can be recognized in time. Assistance for optimal payload usage is available as well.


  • Coverage of the complete circumference of the wheel
  • Unparalleled ease of installation
  • Clamp-on sensors: no drilling/welding/gluing required
  • 100% electromagnetic compatible in any railway environment
  • No electromagnetic interference
  • Self-calibration, self-diagnostic and health monitoring
  • No influence on regular track maintenance
  • Applied in various climate zones, in tunnel environment and on high speed tracks
  • Energy efficient module in compact design
  • Flexibility to add sensors

zentrak Wheel Defect Detection (WDD)

  • WDD sensors measure increased wheel-rail interaction forces coming from running surface defect of passing wheels.
  • Running surface defects create higher wear and tear of both vehicles and infrastructure leading to higher derailment risks. In addition they reduce travel comfort and create an increase in noise and vibration.

zentrak Weighing In Motion (WIM)

  • WIM sensors automatically measure the vertical wheel forces of passing vehicles.
  • In addition derived quantities such as axle load, asymmetric loading, overloading, vehicle weight and train weight are determined.

Technical Specifications:

Train speed: 5 to 450km/h
Train length: up to 5000m
WDD coverage: ~3x wheel circumference
Axle distance: 0.7 to 40m
Wheel diameter: 200 to 1600mm
Vertical static axle load: 2 to 40t
Accuracy of vehicle weighing: up to ±3%
Environment: -40 to +70°C
IP class optical sensors: IP68