Spectrum Averaging vs. More Spectrum Lines --- A Comparative Study of Enhancement Effects on Spectrum

This application note documents a comparative study that investigates the effects of spectrum enhancement achieved by two different approaches: 1) spectrum averaging; and 2) more spectrum lines but no averaging. The major part of the study was done by simulation using signals generated by a DSP software package. Different signals, i.e. broadband white noise and repetitive impulse train, were used in order to reveal the differences of the two spectrum enhancement techniques. Statistic parameters computed on spectral line amplitudes were used to give a quantitative description of the differences and noise reduction performance. Finally, vibration data from an electric motor driving a screw compressor is presented, further confirming the observation in the simulation study.