Visual inspection of an operating machine while vibration testing is important, for valuable clues to machinery condition can often be uncovered. RPM and discharge pressure etc..., should be noted. The following items should be checked:
Are there any unusual noises present?
Are the bearings hotter than normal?
Can you feel any excessive vibration level
Is there anything unusual about the operation of the machine
Are there any fluid or steam leaks obvious?
Do the gauge readings look normal?
Does the machine operator have any comments on the machine condition?