Download a free vibration test guide here. When setting up or managing a vibration monitoring program or condition monitoring program, it is important to document information about the machine and create a vibration test guide.
Here are the important things to document and why:
Nameplate information: It is important to document the make and model of the machine. What happens if you go to test a machine and notice your sensor pads are missing? Was the motor replaced? Was it replaced with a motor of the same make and model or is it a different brand? If it is a different brand, do your vibration alarms and baselines still apply? The machine test guide should be available to the person taking the readings and he or she should periodically verify that the information is correct.
Test Instructions: Vibration analysis in a condition based maintenance program is based on repeatable data. The machine must be tested at the same speed and load every time. It might also be important to control outside influences such as process variables or the effects of nearby machines. In order to ensure that the machine is tested the same way every time, from today to ten years from now when different technicians may be taking the readings, the test instructions must be clearly documented on the test form.
Machine diagram with test points clearly labeled and named: When the data collection technician goes to collect data, he or she needs to know where to take the readings and how to identify the point in the data collector. The machine test guide should contain a picture of the machine (hand drawn is OK) that clearly shows where to take the readings. If you are using test pads or paint marks to identify test points then the document will show you where to replace the pads or marks when they fall off or are painted over. By naming the test point the same way it is named in the data collector the technician will make fewer errors when taking the readings.
When analyzing data from the machine the diagram will come in handy by showing the analyst exactly where the readings on the machine came from. They should be labeled the same way on the test guide as they are in the software.
Machine schematic showing internal components: This can also be a simple hand drawn diagram to help the analyst understand what faults to look for in the machine. Unbalance is a common fault condition, but it looks different in a component that is overhung than it does in a component supported by two bearings. How do you know which it is? You have a schematic of the machine in front of you when you are analyzing the data. No one wants to be the guy who reports a rolling element bearing defect in a machine that has sleeve bearings, so make sure you document the internal components of the machine so you know what faults you are looking for.
Forcing frequencies: In order to analyze data you will need to know how many pump vanes, fan blades, gear teeth etc. the machine has. Use this form to document what you know and don’t know. This will remind you to look for the information you don;t have when the machine is overhauled or when new parts are ordered or even from the vibration data itself.
One of the most common reason why vibration monitoring programs fail is because the so called “expert” leaves and nothing about the program is documented. No one knows which machines in the database are still valid or which baselines are up to date. No one knows how to test the machines correctly or where to take the readings.
If the machine test guide is filled out and kept up to date then it contains enough information for anyone to figure out if the machine in the plant is the same as the one in the database and it give them all the information they need to est the machine in exactly the same way as it was tested before. This is the best way to ensure that your program doesn’t fail even when people leave.
Example Vibration Test Guide
Blank Vibration Test Guide
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