The present paper deals with the measurement of the thickness of the coating on wood using the ultrasonic method, which is based on the measurement of the ultrasonic pulse passage time through the layer. One of the biggest advantages of this method is non-destructive measurement, which allows online quality control during operation, eg when checking paint thickness on window or door frames. During the experiment, the deviations of the coating thickness measured by the destructive and non-destructive method were recorded, however, these deviations were in most cases smaller than the inaccuracy of the optical microscope measurements. The results clearly showed that the accuracy of the described method is sufficient and can therefore be used to measure the thickness of the coating on porous and diamagnetic materials such as wood.



















