High speed non-destructive rail testing with advanced ultrasound and eddy-current testing techniques

Today the rails face increased exposure to heavy loads, higher speeds and a very dense overall traffic. A continued development of testing methods for the rail inspection trains became necessary to match the modern needs for a fast detection and detailed classification of defects. To guarantee the safe operation of rail traffic non-destructive inspection techniques with combined ultrasound and eddy current testing methods are used to detect damages on rails. One of the main actual challenges of automated rail testing is the high inspection speed which is very close to the physical limits. To overcome these limits digital signal processing algorithms have to be used which maintain resolution and detection quality independent of operation speed. This paper presents a recently developed state of the art rail inspection system which uses advanced ultrasonic and eddy current testing techniques. Testing results are shown in a newly developed so called Glassy-Rail-Diagram which is capable to present data with a fixed resolution independent of inspection speed.