The G-Scan is a long range, rapid rail inspection system which is deployed on rail tracks during normal operation. This system uses low frequency guided waves which can travel along the rail and detect defects, such as corrosion, at any location throughout the section including the foot of the rail. The G-Scan is only compatible with the Wavemaker® G4 (32 channels required).

The G-Scan is ideally suited for low frequency guided wave inspection of:

  • Level crossings
  • General rail screening
  • Tunnels
  • Rail welds of all kinds

Principle of Operation

A structure can support many guided wave modes at any given frequency. Each mode carries the guided wave energy in different parts of the rail cross section. Using several modes simultaneously, the entire rail cross section can be inspected in a single test. In addition, by examining which mode is reflected from a defect, it is possible to determine in what part of the rail cross section the defect is located.

Example of guided wave mode shapes with energy concentrated in the foot (left) and web (right) of the rail respectively.

Unlike conventional ultrasonic inspection, guided waves provide 100% volumetric inspection and can inspect tens of metres in a single test.


Number of Channels
Rail Sizes
CEN60, CEN56, CEN54, CEN50
Operating Temperature
-40°C to 120°C (-40°F to 248°F)
Transduction System Compatibility
Wavemaker® G4