The field of machinery diagnostics is quite broad, covering everything from a skilled mechanic’s inspection, to “set point” controls for vibration, pressures, temperatures, and so on, to programmed expert systems. This article will focus on automated machinery diagnostics for vibration.
Vibration analysis started using analog inputs – everything from placing a hand on a machine to “feel” it, to a nickel “standing” on a machine to measure balance quality, to a reed vibrometer which vibrated at a tuned frequency. Later, electronic devices were invented to better measure the level of vibration, and separate the vibration signals into amplitude, period, frequency, and phase. This gave engineers an opportunity to study the signal characteristics of the different types of vibration problems (such as unbalance, misalignment, bearing and gear tones), and write rules defining machine component problems based on the analysis of the vibration signal. Even today, the most common method of machinery vibration diagnostics is a vibration expert manually analyzing the data.
With the growth in computing power, and machinery expertise, vibration tool manufacturers began developing expert software to diagnose vibration problems, using rules-based algorithms, and statistical analysis. Until recently, this still required the end user to the be “expert”, and to program the software to diagnose the problem – in essence, “teaching” the software how to work.
OneProd, with the Accurex™ system, in conjunction with the OneProd suite of vibration measurement tools, has created an effective and accurate system of truly automated machinery diagnostics. The end user only needs to know the basic configuration of the machine (such as an electric motor coupled to an overhung fan), horsepower, and running speed, to set a machine up in the Accurex™ system. No vibration analysis experience is required.
Once the measurements are taken, the Accurex™ system uses two methods to diagnose the quality of the machine vibration:
- ISO Standards (ISO 10816-3) to determine the severity of overall machinery vibration levels,
- Several thousand rules-based algorithms, to determine vibration problems based on the individual characteristics and patterns of the vibration signal.
This is the same method used by human vibration experts, packaged into an automated system.
WHEN TO USE AUTOMATED DIAGNOSTICS
The Accurex™ system can be used:
- As a stand-alone vibration analysis program.
- To supplement an existing program. Since it requires little to no training, it can be used by shift mechanics to diagnose any problems that may develop when the analyst isn’t available.
- By repair shops, to sign off on rebuild work, or to verify machinery quality in the field.
- To test less critical machines, which might not be checked on normal vibration analysis routes.
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