Measurement of RailwayTram Wheel Profiles


PROFILEMETER is an electronic device designed to measure the cross profile of the railway and tram vehicles wheels.

Practical PROFILEMETER applications are as follows:

  • Checking the wheels for their wear,
  • Wheel testing before re-profiling,
  • Measuring of the wheel diameter,
  • Measuring of the vignol rail cross profile.
New features
  • A modification of the profile-meter size were carried out up to the TRA’s conditions
  • The outstanding battery and electronic card were moved into the profile-meter body in order to be as compact as possible
  • Wireless Bluetooth communication makes the manipulation easier
  • New redesigned measuring program under Windows CE for PDA enables a measurement of the complete trains and/or vehicle sets. The collecting of the wheel defects and instantaneous evaluation of the wheel parameters is available
Basic concept of the device

A contact method is applied to determine the wheel cross profile in regular steps of 0.5 mm. The measuring needle can be lowered/raised with a lever on the meter’s front panel.

The PROFILE METER is affixed to the tested wheel with the magnets and adjustable stops. The stops make is possible to measure the wheels having between 500mm and 1250mm in diameter.

The Y-axis sensor and the measuring needle is a part of the rider which moves along a trajectory being perpendicular to the plane of magnets. The spring-mounted needle slides on the measured surface and his movements in YX plane are sensed by two optical encoders.

The rider is powered by the Maxon mini-motor with its gearbox. Motor stop, start-up, and speed are under control of a measuring computer.

The friction coupling protects the motor in emergency event against damage.

The measured values are visualized on the LCD screen of measuring computer in form of the wheel cross profile curve. These data are continuously stored into PDA memory, ready to further processing, graphic representation, and analysis by the PROFIL.EXE program. This advanced software can show up to ten diagrams, to read the co-ordinates, to edit measurement descriptors, to enter mileage traveled, wheel diameter and flange offset.

Within the analysis, the wheel flange width, height, and inclination are calculated. At its output, the analysis gives printed diagrams and tables with account of the wheel values measured.

Measurement Ranges & Accuracy

The X-axis range is given by the adjustable mechanical stops with their end switches. For the trams the X range is from 0 to 100 mm, for railway wheels from 0 to 150 mm. Sensor stop precision at its end position, which defines the origin of co-ordinates (magnet stops), is from 0 to ±0.04mm.

The Y-axis range is given by the measuring point length, being from 0 to 35mm for trams and from 0 to 55mm for railway wheels.

Measuring parameters and precision:


  • Measuring computer: A standard notebook or touch book, Windows 98, or higher. Serial port RS232 is necessary. RAM 512 MB. Alternatively PDA computer PDA – TDS Recon. Windows Mobile 6, 400MHz, 256MB SDRAM, Touch-panel, IP67. Serial communication – RS-232, USB or wireless using Bluetooth.
  • Serial communication: A standard serial cable with CANON 9 connectors for interconnection between the measuring computer and profile meter. Serial port RS232 is necessary. Serial port USB is recommended.
  • Bluetooth: Usually computer PDA TDS Recon is used when Bluetooth communication is applied. There is Bluetooth of class 2, range 10m, data backup on lost of communications
  • Profilemeter: it includes all mechanical parts, electronic card and battery.
  • The charger provided by the suitable cable and connector. Type SSL20C-7612, Input 100-240V, DC Output +12V, 1,67A,

Main Technical Characteristics

  • Electronic system power supply: Ni-MH batteries SANYO 5V, 2500 mAh, weight 0.3 kg covering 7 hour of continuous measuring.
  • Weather conditions: working temperature 0-50°C, for indoor use.
  • Profile meter weight: approx. 3.75 kg.
  • Operating staff: One person.
  • Profile meter fixed on wheel by magnets.