Should you use vibration analysis for condition monitoring?
What is vibration analysis?
Vibration analysis (VA) is generally considered the first technology that could monitor machine health to provide advance warning of failure. The first research article to explore vibration as a way to monitor industrial assets dates back to 1938. Sensors are installed directly on the component to be monitored, and can warn of upcoming failure if they detect vibration patterns that fall outside the range exhibited by a normally functioning piece of equipment.
Vibration analysis sensor technology
Vibration sensors come in different forms, but the most widely used are piezoelectric accelerometers: devices that translate the mechanical force generated by a change in motion into a proportional electrical charge.
Because their sensors must be placed on or near the asset to be monitored, vibration analysis is not suited to monitoring assets:
- located in difficult to reach places e.g. an underground fan in a deep mine shaft).
- located in a remote area or over a large area e.g. pumps located along a remote oil pipeline.
- in hard-to-reach places e.g. a motor encased within a larger machine.
- in hazardous environments e.g. ATEX zones.
- that operate under harsh conditions, such as the hot and humid conditions of a paper machine, where the sensors could be subject to damage or destruction.
How accurate is vibration analysis in detecting developing asset faults?
Below is a P-F curve demonstrating how vibration analysis compares to other condition monitoring techniques when it comes to fault detection in advance of an asset breakdown. This is a P-F curve for bearing failure in a specific production system.
The locations of the various technologies on the curve will be different for each piece of equipment, production environment and failure mode, so be sure to calculate it for the specific assets and types of degradation you want to monitor.
For more information on the accuracy of vibration analysis in comparison to other condition monitoring techniques, download the condition monitoring comparison guide.
What can vibration analysis monitor/detect?
Every production system is different, meaning there’s no one-size-fits-all condition monitoring technology. However, we can state some general rules when it comes to areas where vibration analysis is strong or weak in asset monitoring.
Strong in monitoring:
- one motor driving many assets
- mechanical faults
- direct current (DC)
- rotating machinery
Poor in monitoring/unable to monitor:
- remote or inaccessible assets
- assets located in ATEX zones or other harsh conditions
- assets located in noisy or vibrating environments
- electrical faults
- very slowly rotating machinery
- energy efficiency
How does vibration analysis compare to other condition monitoring techniques?
Download the condition monitoring comparison guide for a full comparison of vibration analysis and the following widely used techniques:
- Acoustic analysis
- MCSA (motor current signature analysis)
- MCSA + voltage
- Oil analysis
- Infrared thermography
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