Vibration Severity Chart
Vibration Severity Chart to determine acceptability of vibration levels measured.
Values shown are for filtered readings taken on the machine structure or bearing cap.
When using the Machinery Vibration Severity Chart, thefollowing factors must be taken into consideration:
1. When using displacement measurements only filtered displacement readings (for a specific frequency) should be applied to the chart. Unfiltered or overall velocity readings can be applied since the lines which divide the severity regions are, in fact, constant velocity lines.
2. The chart applies only to measurements taken on the bearings or structure of the machine. The chart does not apply to measurements of shaft vibration.
3. The chart applies primarily to machines which are rigidly mounted or bolted to a fairly rigid foundation. Machines mounted on resilient vibration isolators such as coil springs or rubber pads will generally have higher amplitudes of vibration than those rigidly mounted. A general rule is to allow twice as much vibration for a machine mounted on isolators. However, this rule should not be applied to high frequencies of vibration such as those characteristic of gears and defective rolling-element bearings, as the amplitudes measured at these frequencies are less dependent on the method of machine mounting.