In-Track Measuring System (IWMS)

The In-Track Measuring System (IWMS) system is a measuring system that is integrated into the track.

In-Track Measuring System (IWMS)

With the help of its international partners, ADOR Tech designs and manufactures an In-track measuring system (IWMS) integrated into the track. This system records the profile of each wheel in real-time with an accuracy of ± 0.05 mm. The measurement is made while the train is crossing.

The In-track measuring system uses the wheel profile to calculate all critical wheel and axle parameters, such as:

  • Wheel flange height and thickness
  • qR dimension
  • wheel width
  • AR dimension
  • hollowness
  • wheel diameter

The IWMS system can be installed inside the depot without modifying the rails. Adapting to the local space and the special regulations of the individual depots is just as possible as the installation outdoors.


Indoor-In track measuring system/ Outdoor-In track measuring system


  • In-track installed online measuring instrument for wheel profiles
  • Easy integration with only slight modifications to the existing rail
  • Recording and qualitative evaluation of the complete wheel profile whilst driving over
  • Immediate determination and display of wear characteristic dimensions
  • Wear analysis
  • Maintenance forecast
  • It can be used for railways and tramways, including low-platform vehicles
  • Online laser measuring system for monitoring wheel profiles in-track


  • Contactless measurement
  • Accuracy of ± 0.2 mm for the profile and ± 0.5 mm for the diameter
  • Available for indoor and outdoor installation
  • No civil work required
  • Adaptable to almost any type of wheel/ fleet/ location
  • Robust against the presence of sanders, electromagnetic brakes, etc.
  • The results are obtained in real-time immediately after the train passes.
  • Software tool included in order to manage measured data, analyze wheel wear, generate reports, trigger automatic warnings/alarms via SMS/e-mail, etc.

At ADOR, as Dr. D. Wehrhahn's representative in Canada, we have integrated our engineering and commercial expertise to provide customers with tailor-made solutions. We are ready to provide technical and engineering services for sophisticated and complex necessities of every inquiry based on the skills and experience of our staff, resources, and capacities. Get in touch to discuss your requirements!

Measuring principle and system concept

IWMS system has a modular design and is composed of two different subsystems dedicated to the reconstruction of the wheel profiles of each side of the track.

Each subsystem comprises two or three independent modules containing machine vision cameras and their corresponding lasers. These camera-laser modules provide the appropriate information needed to generate the complete profile of the wheel. The number of modules of the IWMS system depends on whether it integrates wheel diameter measurement.

Wheel diameter measurement

IWMS system can optionally measure wheel diameters. The accuracy of this mea­surement depends on different aspects analyzed for each situation, such as lo­cation, fleet characteristics, speed of the trains, wheelset size, etc. However, an accuracy of ±0.5 mm can be achieved under normal circumstances.

The complete wheel profile is measur­ed using two OPTImess 2D laser sheets of light sensors, whereby one sensor measures the inside flat surface up to the top of the wheel flange and the second sensor the side of the wheel profile facing the rail. Both partial profiles are joined together in the processing computer, and the profile parameters, such as SD, SH, qR, etc., are determined from this.

Speed measurement

IWMS standard system can generate the wheel profiles of trains traveling at speeds up to 15 Km/h; it can be adapted to operate at speeds >90 Km/h. Additionally, the IWMS system allows measuring the train's speed when the wheel profiles are obtained with an accuracy of 5%.

In-Track Measuring System (IWMS) Applications:

  • wheel flange height, thickness, and qR dimension
  • wheel width
  • back to back distance Ar
  • track and guide dimension calculation
  • wear history
  • limit comparison
  • nominal and actual profile comparison
  • profile co-ordinates of every wheel
  • measurement of wheel diameter
  • monitoring of the diameter differences of the wheels on the whole vehicle, the drives, and bogies
  • interfaces for data transfer with central EDP systems, e.g., SAP
  • vehicle detection by transponder

Technical Details

Listed below are the general technical specifications of our In-Track Measuring System (IWMS). For the complete specifications in details, please download the catalog at the bottom of the page.

Measurement type: contactless

Speed ranges: 3 to 45 km/h

Profile measurement SH: +/- 0.2 mm

Profile measurement SD: +/- 0.2 mm

Profile measurement qR: +/- 0.2 mm


Please enter your information to download our In-track measuring system (IWMS) catalog.