The Wheel Qualification Machine (WQM) is regarded as an integral part of a rail maintenance workshop and is invaluable in determining the processing required for wheels.
The machine will automatically load the wheelset, spin it at the correct speed, measure the wheel diameter, apply the UT probes for the test and unload the wheel when finished.
The WQM tests the wheels using two EPOCH 4 ultrasonic flaw detectors, which detect the ultrasonic signal and also measure for distance.
The system will analyse the echoes, those expected such as the ‘Back Wall Echo’ or echoes from discontinuities such as shelling or cracking.
Discontinuities are then classified as acceptable or unacceptable (defects) depending on their length, their location in the rim, and their location in relation to other discontinuities.
Each wheel is then given a "Severity Level", with an associated “Corrective Action".