  This novel work investigates the influence of the inspection system
acceleration on the leakage signal in magnetic flux leakage type of
non-destructive testing. The research is addressed both through designed
experiments and simulations. The results showed that the leakage signal,
represented by using peak to peak value, decreases between 20% and 30% under
acceleration. The simulation results indicated that the main reason for the
decrease is due to the difference in the distortion of the magnetic field for
cases with and without acceleration, which is the result of the different eddy
current distributions in the specimen. The findings will help to allow the
optimisation of the MFL system to ensure the main defect features can be
measured accurately during the machine acceleration. It also shows the
importance of conducting measurements at constant velocity, wherever possible.
