Abstract:
The paper presents the problem of frequency measurement of periodical signals by using the counting of zero crossings of those signals. Theoretical principles are used in order to implement one frequency meter instrument. Because this operation needs digitizing of the measured signal, and it is desired as the proposed instrument to measure a wide range of frequencies with a minimum resolution, o method for aliasing detecting is presented. Thus, if the signal frequency becomes larger than one half the sampling frequency, the user is informed and the sampling frequency is increased.