A booklet covering Required Vibration Analysis Techniques & Instrumentation on High-Speed Machines (37 page booklet)
Highlights:
This paper covers how high frequency vibration analysis should be performed including what analyzer types, transducers, instrument specifications and transducer mounting techniques should be employed.
It also covers special diagnostic techniques required for high frequency analysis and describes what sets apart detection of problems on sources generating these high frequencies from those that generate more nominal frequencies in the region of 20 to 2000 Hz (1200 to 120,000 CPM). Primarily throughout the paper, the term "High Frequency" will refer to machines having vibration frequencies greater than or equal to 10,000 Hz (600,000 CPM).
Some of these machines themselves do not necessarily have high operating speeds, but have components within them which generate these high frequencies.
Machines generating such high frequency vibration and covered in the paper include examples such as centrifugal air compressors which have a number of sources generating frequencies much greater than 10,000 Hz, some of which are elaborated in tables.
This includes the fundamental gear mesh frequency (GMF) of the gear set in these compressors which is often over 20,500 Hz (1,230,000 CPM).
This paper also covers evaluation of other high frequency machinery such as refrigeration chillers outfitted with gearing having fundamental gear mesh frequencies of approximately 8330 Hz (500,000 CPM).
This paper points out gears require frequency spans encompassing 3.25X GMF which may demand measurements exceeding 70,000 Hz (4,200,000 CPM) on machines such as the centrifugal air compressors.
Thus, major emphasis is focused on what types of transducers are required, how they must be mounted, how to detect unwanted "noise" in these measurements, etc. without employing the information provided in this paper, information and data critically needed to assess the condition of such high speed machinery can be lost altogether.
