Severity determination is one of the most difficult tasks a vibration analyst faces. Several methods can be used to help identify the severity of defects identified in vibration data.
One method is to consider the amplitude of the defect. This usually works well but does not always correctly identify the severity of the problem. Another method is to look at the G swing (peak-peak value) in the time waveform data that has been collected. An additional method is to trend the data and look for increases in trend values between data collection intervals. The rate of change shown in the trend data can be a very good indicator of the progression of the identified defect.
A combination of methods usually works best to help identify the severity of a defect. However, it is always best to report the defect condition for repair as soon as it has been identified. This provides as much time as possible to properly plan and schedule repairs as may be required.