Here are some more reasons to consider an online vibration monitoring system.

1. High Accuracy: Primarily in machining processes,  or for highly precise machinery that has no tolerance for deviation,  online systems can provide advance early warning of developing problems and other critical information as to operating conditions, correlate conditions that can lead to problems in production quality and provide the clues required to avoid recurrence of future problems.
2. Quality Control: Cost has historically been a limiting factor in this area. Most QC relies on a trained eye, or post production inspection and measurement. An online system may provide real-time QC information as product is being made, as problems are being caught, or before a batch or a production run has to scrapped, re-worked or treated as “seconds”.
3. Repeatability: With data collected from an online system, one always gets consistent data from the same sensor mounted at the same angle, with the same pressure, time after time. The only real change from one reading to the other, once adjusted for changes in operating parameters, is the condition of the machinery itself. An online system will capture very small deviations long before  they turn into problems. This is especially valuable on very sensitive equipment.
4. Always on: An online condition monitoring system delivers data with never a break and is always available. A complete set of data is obtained instead of mere chunks of data sporadically collected by hand.
5. Protection: Online systems can be configured to enable an output relay upon alert and/or absolute fault. This is something that is best done after some time has been spent looking at the historical data and trends. Establishing “alert” and “alarm” levels can protect the equipment being monitored. You can also use an output relay to a flashing light or audible alarm.
6. Intermittent Duty: Much time is wasted waiting for a machine to reach a steady state or run at a certain speed or run at all when collecting route-based vibration data. An online system will run the route unattended, and can be set to collect data only when certain parameters are met such as a certain speed or temperature, or at particular times.
7. Remote Diagnostics: Online systems permit remote or off-site analysis of data, reducing dependence on local expertise. It is therefore easier to trend, correlate and diagnose.
8. True Machinery Condition: Vibration is conditional and subject to many variables such as speed, load, temperature, pressure, power supply, valve condition etc. An online system can record and store these additional inputs and can trend and cross reference this data.

Thanks to Jay Gensheimer with Solute LLC for this valuable post.