Coupling misalignment is a condition where the shaft of the driver machine and the driven machine are not on the same centerline. The non-coaxial condition can be parallel misalignment or angular misalignment. The more common condition is a combination of the two in both the horizontal and vertical direction. We are forced into this situation of coupling alignment because equipment from different suppliers must be mated together. Misalignment is temperature dependent. All materials expand with increasing temperature, and metal is no exception. Motors warm up several degrees, and the driven machine may warm up or cool down from ambient depending on the fluid it is handling.
This experiment teaches how parallel misalignment in a system is monitored based on vibration.