Delphin ProfiMessage - 9.2.4 FFT analysis;frequency spectrum

ProfiMessage
Formeasurementsusingaccelerationsensors,avibrationvelocitysignal(unit
m/s2)isconvertedintoavibrationspeedsignal(unitmm/s).Refertothe"Applic-
ationsusingAMDT"manual.
Restrictions
Thedigitalintegratorisalsosubjecttotheserestrictions:
l BoardV2.00toV2.12
For1...4analogueinputs:Integratoravailable
For5...8analogueinputs:Integratornotavailable
l BoardV2.13andhigher
For1...8analogueinputs:Integratoravailable
Whendigitalintegrationisenabled,measurement-rangecheckingor
wire-breakmonitoringwillnottakeplace.
9.2.4 FFTanalysis/frequencyspectrum
VibrationsignalrecordingsareinitiallysavedtoabufferwithintheI/Omodule.
OptionsareavailabletothenperformanFFTanalysisortocomputeafrequency
spectrum.Eachanalogueinputchannelisprovidedwithanadditional“FFT/spec-
trum”channel.Thisdeliversablockofmeasurementdata(e.g.800amplitudeval-
uesconcerningfrequency).
Properties
l An“FFT/spectrum”channelcanbecreatedseparately(foreachanalogue
input).
l FFTalgorithmsfor1024,2048,or4096pointsorwith400,800,or1600
lines.
l Frequencyrange,numberoflinesandfrequencyresolutioncanbeset.
l Standardwindowfunctions'Hanning','FlatTop',etc.canbechosen.
l Datacompressioncanbeusedfortransmissionandstorage.
Scaling
“FFT/spectrum”channelscanbeindividuallyscaled.Scalingtakesplaceinthe
requiredunit(e.g.±100µmfordistance/clearancesensorsor±50gforaccel-
erationsensors).
Application
Analysisofcharacteristicfrequenciesandtheiramplitudesforameasuredvibra-
tionsignal.
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Delphin Technology AG
Dezember 2015
ProfiMessage Manual