One of the most important aspects of data collection in a vibration or virtually any program is data quality and repeatability. If one cannot be certain that the data is good, one cannot be certain that the results based on that data are good either; garbage in equals garbage out, or so it is said. This is especially true if one is trending vibration readings in a Predictive Maintenance program.
The goal in a Predictive Maintenance program is to have repeatable readings, year in and year out, regardless of who collects the data. One of the first steps to accomplish this is to properly define test locations. The best available solution to this in a walk around vibration program is to mount sensor pads on the machine in the proper locations and create a diagram of the machine indicating where these test locations are and how the test pads are oriented. This will allow them to be properly replaced if they are knocked off.
The best place to locate these test pads are on rigid surfaces as close to the bearings as possible. Don’t places test pads on cowlings, motor housings or any other non-rigid structures. Test pads should be affixed using a rigid adhesive to assure good data transmission.