Vibration Analysis is a powerful tool for early fault detection as well as an excellent starting point for implementing a Predictive Maintenance program. Unfortunately, it is frequently the most misapplied technology of all the condition monitoring tools. In our 30+ years of experience in Vibration Analysis, here are three of the most common ways that we have seen this valuable technology misapplied:
- Improper accelerometer mounting
Mounting an accelerometer correctly is key to obtaining reliable data. Too often, when placing the accelerometer, technicians allow the device’s magnet to pull the accelerometer out of their hand and slam it down onto the machine. Doing so does two things: it disturbs the settling time needed by the accelerometer before accurate data can be taken and it can be damaging to the accelerometer itself. The proper way to mount an accelerometer is to bring it close to the machine at a side angle so the magnet doesn’t pull the device from your hand and gently tip it onto the machine.
- Improper monitoring techniques for specific machine types
Many times, we find customers who have a Vibration Analysis Program and are routinely collecting data on equipment but have databases that are set up too generically. Database setups define the vibration test data results captured while taking route-based samples. Therefore, these databases need to be specifically tailored for each machine type being monitored. All too often only speed is used to differentiate measurement types from machine to machine, resulting in improper Frequency Ranges and Lines of Resolutions being collected for analysis. This leads to many missed diagnoses, increases in time for taking additional “off-route” data, and limits the ability for early fault detection.
- Using vibration analysis more reactively than proactively
Over time, companies lose sight of the value of vibration analysis as a tool of Predictive Maintenance and start using it as more of a reactive maintenance tool. For example, simply using vibration analysis data to find a bearing defect in a machine and then scheduling it for repairs without utilizing that information in a Root Cause Failure Analysis. One could argue that the technology “predicted” a potential catastrophic failure, but without the Root Cause Failure Analysis, you are still simply “reacting” to a failed bearing. The PdM data needs to be used to its fullest in order to obtain maximum cost reductions and payback to the facility by actually providing answers to why equipment fails in the first place. The information then can be used by the reliability program to implement changes that will actually “prevent” future failures of this type from occurring.
Most failure modes can cause an increase in vibration. That’s why Vibration Analysis is the predominant and most widely used method to determine equipment conditions and predict failures. However, if not performed correctly, the value of this technology is significantly diminished. For more information on vibration analysis and its benefits, contact us.