Abstract: A portable vibration monitoring device (10) for use in connection with a base computer (11) which stores data regarding the nature and parameters of vibration measurements to be made on preselected machines for predictive maintenance purposes. The device includes a power module (36) which energizes the various components. A vibration sensor (14) produces an analog signal which is representative of selected vibration parameters. The signal generated by the vibration monitor is conditioned by a signal conditioning module (16) which includes anti-aliasing filters which enhance the accuracy of the data collected. A multiple function module (18) includes various selectively energized modules which enhance the speed and reliability of the data collected. This data is analyzed by a microprocessor and displayed as desired.