Description

Acceleration measurement and determination of therelevantfrequency, the acceleration and the amplitude of theoscillationExplanation of the buttons arranged on top of the screenCONTI:Continuous measurement 5 SEC: Fixed measurement duration of 5sec,then STOP automatically STOP: Stop of measurement, the last5seconds are displayed -: In stop mode, move zoom window(1.28sec)to the left, only for PRO version +: In stop mode, movezoom window(1.28sec) to the right, only for PRO version There aresevenfigures below the buttons. Upper figure "Currentaccelerationvalues": The accelerations values are displayed. Thesamplingfrequency of most smartphones is 50 Hz. If the actualsamplingfrequency deviates by ± 1 Hz, then the actual samplingfrequencyappears (flashing). Different times must then becorrectedaccordingly. The numerically displayed measured valuesarecorrected automatically. During a swipe action "from bottom lefttotop right", the APP goes into a diagnostic mode. Then theactualsampling frequency, the standard deviation of thesamplingfrequency and an internal counter appear. Underneathfigure"Accelerations over time": It shows the accelerations curveof thelast 5 seconds. After pressing STOP, a window of 1.28 sec ismarked(vertical black bars). in PRO version: the window can bemoved by±, after a double-tap on the figure it appears twice aslarge,after another double-tip it is resized again. Swipe up, swipedownto change the scaling. Underneath figure "Largest of thethreeacceleration components curve": It shows the accelerationcomponentwith the maximum acceleration change. The zoom windowisrepresented by 1.28 sec. It is particularly suitableforoscillation frequencies from 1 Hz to 15 Hz. The more sinusoidalthetime signal, the more secure are the determined values.Indiagnostic mode, trigger points and sine approximationsarevisible. In PRO version: after a double tip on the figureitappears twice as large, after another double-tip it isresizedagain. Swipe up, swipe down to change the scaling.Underneathfigure "Numerical evaluation from the time signal":Hereevaluations from the time domain are displayed numerically. Inthediagnostic mode, the number of detected vibrations aredisplayed.Sx is their standard deviation. The larger n and smallerSx, thesafer the values determined. The acceleration amplitudealsospecifies a standard deviation. The calculation is done withtheleast square method. Underneath figure "FFT-writing oftheacceleration over time": Here, a plot of the accelerationspectrumover time is shown. Shown are the last 5 seconds. The zoomwindowis marked. In PRO version: after a double tip on the figureitappears twice as large, after another double-tip it isresizedagain. Swipe up, swipe down to change the intensityscale.Underneath figure "FFT spectrum of the zoom window": It showstheFFT spectrum within the zoom window. The black curve istheresulting acceleration. In PRO version: after a double tip onthefigure it appears twice as large, after another double-tip itisresized again. Swipe up, swipe down to change thescaling.Underneath figure "FFT, numeric": It is the numeric outputof theFFT spectrum within the zoom window. The maximum of the FFTisindicated by a cross. Frequency, Amplitude and maximumaccelerationvalues are shown.