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Thirty years ago I worked for a company by the name of IRD Mechanalysis.
Their business was vibration detection, monitoring and analysis for preventive maintenance of heavy machinery. At that time they were a subsidiary of H H Robinson Company, a construction company based in Pittsburgh PA. We built our own crystal-transducers to work with the monitoring equipment. I never worked in the analysis end of the business, so I cannot tell you where the frequencies indicating "good" and "bad" lie. Each device is different. A problem with each component was indicated by a different frequency. The only aviation use I am aware of was to dynamically balance props. Jim Weir wrote: I've come across a marvelously cheap vibration sensor that I want to convert into an engine vibration instrument for a Kitplanes article. The electronics for me is relatively trivial...the mechanics of vibration are a little harder to fathom. From a mechanical engineering point of view on a horizontally opposed engine, there are (as with most things) three axes of freedom -- fore and aft, side to side, and up and down (longitudinal, lateral, vertical). The sensor I have reads two axes, and my hit is that fore-aft is the least interesting vibration mode of the engine. The question is whether to have a two-channel meter (which complexes up both the design AND the panel space), a single meter switchable between lateral and vertical) or a single meter with the two axes summed together. Comments and thoughts from the technonerds amongst us appreciated. (It has nothing, repeat NOTHING to do with the fact that such a meter might have detected a crack in that cylinder WAY BEFORE it departed the engine on the way home from Oshkosh {;-) ) Jim Jim Weir (A&P/IA, CFI, & other good alphabet soup) VP Eng RST Pres. Cyberchapter EAA Tech. Counselor http://www.rst-engr.com |
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john smith writes:
Thirty years ago I worked for a company by the name of IRD Mechanalysis. Their business was vibration detection, monitoring and analysis for preventive maintenance of heavy machinery. I remember them. We used it on pumps. Here "pump" mean 17-stage centrifugal with a 800 HP motor that runs on 3-phase 4160vac. As I recall, it took a fair amount of training to interpret the results. -- A host is a host from coast to & no one will talk to a host that's close........[v].(301) 56-LINUX Unless the host (that isn't close).........................pob 1433 is busy, hung or dead....................................20915-1433 |
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