Practical Solutions to Machinery and Maintenance Vibration Problems
Chapter 12, Low Frequency Vibration
Section 3, Summary
A different approach to vibration tolerances and evaluations is needed for low speed machines. The lower the speed or frequency being measured, the more precautions are needed. For most machines, velocity units are preferred, but for low speed machines, displacement is the preferred measuring unit. Low speed vibration may also require either special transducers or the use of correction factors.
Another important point to reemphasize: even for medium and high speed machines, where velocity is most often the preferred vibration unit, there are special situations where displacement is best. For example, the displacement motion between two papermachine rolls or metal rolling rolls create waves or "bars" in the final surface. The same applies for woodworking cutterheads, metalworking cutters, grinders and the like.
This textbook contains only part of the information in our Practical Solutions seminar.