Research of fast sheet thickness measurement with EMAT

To solve poor adaptability of traditional thickness measurement method in sheet thickness measurement, a fast sheet thickness measurement method combining electromagnetic acoustic resonance (EMAR) is proposed. Because of the inverter signal, the new method can get a relatively complete frequency spectrum with only one excitation. The difference of sine waves and square waves have been analyzed by simulation. In the end, an experiment has been made to measure aluminum plates whose thickness are 1mm, 2mm, 2.9mm, 5mm. Results show that the fast sheet thickness measurement method can measure the thickness of sheet efficiently and rapidly with an absolute error below 0.1mm.