Off-Road Machine Operator Vibration Measurement Methods

Analysis of off-road machine operator vibration data shows that the methods of absorbed power and amplitude-frequency distribution provide no information beyond that expressed by the frequency weighted overall rms acceleration of SAE J1013 JAN80 and ISO 2631. The probability density functions of the data are Gaussian in both broad band and narrow band analysis. “Crest factor” is a meaningless descriptor of the data. As shown by examples, failure to consider the statistical precision of the random data results in erroneous time domain and frequency domain statistics.