Configuring Absolute Vibration in Displacement vs Velocity vs Acceleration

[VibroSystM - Service]

Configuring the system in displacement implies a double integration calculation (from acceleration to velocity and then from velocity to displacement) seeing that the fiber-optic accelerometers provide a raw signal proportional to the acceleration. This processing can amplify the low frequency results to some extent. These low frequencies represent very little energy and unless at very high amplitudes, are not of consequence for the Unit.

If only a protection scheme is desired/required then the configuration of choice would be velocity. Most standards for absolute vibration are expressed in velocity. This is because, contrary to displacement, a result at high frequency represents the same energy as low frequency. For example, 1 mm/s at 120 Hz is the same energy level as 1 mm/s at 10 Hz. On the other hand, 200 µm, pk-pk at 120 Hz represents much more energy than 200 µm, pk-pk at 10 Hz. With this discrepancy in displacement, it is difficult to define alarm levels to protect the higher, more damaging frequencies.

However, seeing that the ZOOM system has the capability to monitor and alarm solely on specific frequencies, it is possible to configure in acceleration (Gs, peak) and configure individual/varying alarm levels based on the frequency.