The digital mean value filter is designed to measure the wave hight by withdrawing the needed part from the mean value of a mixed signal, provided the wave shape of a real signal is known. It has a very important application to the data processing of the dynamic electronic track scale signal. This fillter works by the way of digital filtering. In this paper, the fundamental relations of the mean value filter are discussed and the functions of window adjustment described. It is shown that, under proper conit...