Simplified Data Acquistion and Analysis
While providing many advantages, simplified data acquisition and analysis can also be a liability. Because technician involvement is reduced to a minimum, the normal tendency is to use untrained or partially trained personnel for this repetitive function.

Single-Channel Data
Most of the microprocessor-based vibration-monitoring systems collect singlec channel,steady-state data that cannot be used for all applications. This limitation prohibits the use of most microprocessor-based vibration analyzers for complex machinery or machines with variable speeds.

Steady-State Data
Most of the microprocessor-based instruments are designed to handle steady-state vibration data. Few have the ability to reliably capture transient events such as rapid speed or load changes. As a result, their use is limited in situations where these changes occur.
Them most serious limitations created by averaging and the anti-aliasing filters are the inability to detect and record impacts that often occur within machinery. These impacts generally are indications of abnormal behavior and are often the key to detecting and identifying incipient problems.

Frequency-Domain Data
While frequency-domain data analysis is much easier to learn than time-domain data analysis, it cannot isolate and identify all incipient problems within the machine or its installed system.

Low-Frequency Response
Many of the microprocessor-based vibration-monitoring analyzers cannot capture accurate data from low-speed machinery or machinery that generates low-frequency vibration. Specifically, some of the commercially avilable analyzers cannot be used where frequency components are below 600 cycles per minute(cpm) or 10HZ.

Averaging
All machine-trains are subject to random, nonrecurring vibrations as well as periodic vibrations. Therefore, it is adviasble to acquire several sets of data and average them to eliminate the spurious signals. averaging also improves the repeatability of the data because only the continuous signals are retained.

Overlap Averaging
Many of the microprocessor-based vibration-monitoring systems offer the ability to increase their data acquistion speed. This option is referred to as overlap averaging. Although this approach increases speed, it is not generally recommended for vibration analysis.

Excluding Machine Dynamics
To achieve maximum benefits from vibration monitoring, the analyst must understand thelimitations of the instrumentation and the basic operating dynamics of machinery. Without this knowledge, the benefits will be dramatically reduced.

Application Limitations
The greatest mistake made by traditional application of vibration monitoring is in its application. Most programs limit the use of this predictive maintenance technology to simple rotating machinery and not to the critical production systems that produce the plant's capacity. As a result, the auxiliary equipment is kept in good operating condition, but the plant's throughput is unaffected.
Vibration monitoring is not limited to simple rotating equipment. The microprocessor-based systems used for vibration analysis can be used effectively on all electro-mechanical equipment-no matter how complex or what form the mechanical motion may take. Return