Author: Grant Healy

While working with a customer recently, I encountered a question I’ve heard countless times especially from Condition Monitoring Technicians who are transitioning into online vibration analysis:
“Why are my overall vibration values moving around so much?”
“Why do they vary so much?”

At first glance, the fluctuations in vibration data can feel overwhelming particularly for those used to periodic data collection. The sudden visibility into high-frequency, high-density data exposes variability most people never realised existed. And that moment often becomes a turning point: when a technician realises they actually had very little insight into how the machine behaves throughout an entire production cycle.

Figure 1:Vibration Analysis Snapshot
From Micro to Macro: A Shift in Mindset

It’s easy to get caught in the trap of focusing on micro-level anomalies (e.g. a spike in a trend or individual time waveform) and spend hours chasing down a root cause that may not even exist. I know this well because I’ve been there. As someone who started out collecting vibration data manually, I used to rely heavily on pattern recognition, field experience, and gut instinct. I rarely gave much thought to the natural variability of machine data largely because I never had access to this level of detail before.

But online monitoring changes the game. It demands a shift from a micro mindset where every fluctuation is a cause for concern to a macro perspective that embraces patterns over time and views variability as part of a broader operating fingerprint. 

Case in Point: The Cooling Tower Fingerprint

Take the image below as an example. This is data from a cooling tower, a relatively simple, steady-state machine. Daily, the acceleration vibration RMS levels rise and fall in a predictable, cyclic pattern, almost like a temperature trend.

If we were using a handheld data collector, this kind of trend would likely go unnoticed or be dismissed and attributed to ‘human factors’ such as different technicians collecting the data, inconsistencies in sensor mounting location .

With online monitoring, we can clearly see that this fluctuation is part of the machine’s normal operating rhythm. From a micro viewpoint, these daily ups and downs might look like instability. But from a macro perspective, it’s the machine’s heartbeat and it’s perfectly healthy. 

Let the Trend Mature

When you’re just beginning to collect continuous data, it’s important not to overreact to every spike or dip. As a general rule of thumb:

If there’s no significant change in operating conditions, and the values return to baseline within the next one or two readings, give the data time to settle before drawing conclusions.  Make sure you understand the normal operating range of the machine, before jumping to conclusions.

Large data sets mean our understanding of machine operations needs time to mature.  Only then can they reveal patterns and insights that simply aren’t visible with periodic data collection.  It is important that we configure our automated alerts and alarms once we have a full understanding of the machine’s operational behaviour.

Author: Grant Healy

While working with a customer recently, I encountered a question I’ve heard countless times especially from Condition Monitoring Technicians who are transitioning into online vibration analysis:
“Why are my overall vibration values moving around so much?”
“Why do they vary so much?”

At first glance, the fluctuations in vibration data can feel overwhelming particularly for those used to periodic data collection. The sudden visibility into high-frequency, high-density data exposes variability most people never realised existed. And that moment often becomes a turning point: when a technician realises they actually had very little insight into how the machine behaves throughout an entire production cycle.

Figure 1:Vibration Analysis Snapshot
From Micro to Macro: A Shift in Mindset

It’s easy to get caught in the trap of focusing on micro-level anomalies (e.g. a spike in a trend or individual time waveform) and spend hours chasing down a root cause that may not even exist. I know this well because I’ve been there. As someone who started out collecting vibration data manually, I used to rely heavily on pattern recognition, field experience, and gut instinct. I rarely gave much thought to the natural variability of machine data largely because I never had access to this level of detail before.

But online monitoring changes the game. It demands a shift from a micro mindset where every fluctuation is a cause for concern to a macro perspective that embraces patterns over time and views variability as part of a broader operating fingerprint. 

Case in Point: The Cooling Tower Fingerprint

Take the image below as an example. This is data from a cooling tower, a relatively simple, steady-state machine. Daily, the acceleration vibration RMS levels rise and fall in a predictable, cyclic pattern, almost like a temperature trend.

If we were using a handheld data collector, this kind of trend would likely go unnoticed or be dismissed and attributed to ‘human factors’ such as different technicians collecting the data, inconsistencies in sensor mounting location .

With online monitoring, we can clearly see that this fluctuation is part of the machine’s normal operating rhythm. From a micro viewpoint, these daily ups and downs might look like instability. But from a macro perspective, it’s the machine’s heartbeat and it’s perfectly healthy. 

Let the Trend Mature

When you’re just beginning to collect continuous data, it’s important not to overreact to every spike or dip. As a general rule of thumb:

If there’s no significant change in operating conditions, and the values return to baseline within the next one or two readings, give the data time to settle before drawing conclusions.  Make sure you understand the normal operating range of the machine, before jumping to conclusions.

Large data sets mean our understanding of machine operations needs time to mature.  Only then can they reveal patterns and insights that simply aren’t visible with periodic data collection.  It is important that we configure our automated alerts and alarms once we have a full understanding of the machine’s operational behaviour.

Final Thought

Online vibration analysis provides the insight to a machine’s ‘heartbeat’.  It’s more than just numbers, it offers understanding. And once you learn to read that rhythm, you gain a much deeper, more confident insight into machine health than ever before.

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