Vibration analysis vs MeterWorks Vibrometer

The application analyzes the data from the phone's accelerometer and builds a vibration spectrum. This allows the evaluation of not only the strength and frequency of the vibration, but also the speed of rotation of various mechanisms: fans, motors, various rotating components; since the vibration frequency often (but not always) coincides with the frequency of rotation. The application will be useful in determining the quality of fans and motors, in determining whether their actual parameters coincide with the ones declared by the manufacturer, it will find its uses in monitoring of malfunctions (e.g. in bearings) or while testing the quality of assembly and balancing of the homemade mechanisms with rotating parts. Do not expose your iPhone to an excessive vibration, as it may break. If the analyzed vibration is too strong, use a foam material pad, or put your iPhone at a distance where the force of the vibration is not dangerous to your device. In addition to decreasing vibration for the iPhone, a foam pad improves contact between the iPhone and the vibrating part, which makes the transmission of vibration more accurate and produces better results. BE SURE TO READ THE EXAMPLES OF THE VIBRATION SPECTRUM ANALYSIS AT THE APPLICATION WEB SITE (usefulmobileapps.com). Features of the full version of the application: • The choice of units of measurement. X-axis: Hz or RPM. Y-axis: g, m/s², ft/s², mm/s, in/s (ips), mm, mil, dB(A), dB(V). • FFT size (for built-in accelerometer): 64, 128, 256, 512, 1024, 2048, 4096 (data collection time from 0.64 sec. to 40 sec.). For an accelerometer connected to the headphone jack FFT size from 2048 to 131072. For Bluetooth-accelerometer FFT size from 512 to 32768. • Linear and logarithmic frequency scale. • Linear frequency scale with maximum details (there is a choice for the displayed frequency range). • Peak frequency detection. • Values of any point (for frequency scale and sound wave (at maximum detail)). • Selecting which axis of the accelerometer is to collect data. • Octave bands (1/1,1/3,1/6,1/12). • Window functions (Blackman, Hamming, Hann (Hanning), Blackman–Nuttall, Gaussian, Flat top). • Peak hold. • Exponential spectrum averaging. • Taking a screenshot by lightly touching the screen. • Root mean square (RMS, for vibration) or average value (AVG, for absolute values) for vibration wave. Values are calculated only for data displayed on the screen. • Calibration of the built-in accelerometer. Need EXCLUSIVELY for measuring absolute acceleration values (gravitational acceleration). To activate the settings, turn on the "Vibration wave" mode and turn off the "Only fluctuations" mode. The parameters of the accelerometer depend on the temperature and voltage of the battery, and may change over time. To obtain stable values, the accelerometer should work for several minutes. • Saving the measurement results in the application. Files with saved data (SavedData_[date]_[time].txt) can be copied to a desktop/laptop computer or transferred to another iPhone using iTunes. • Export data to a text ("Y=[y1 y2... yn]", "y1;y2;... yn", "x1;y1\nx2;y2;...") or WAV file. Number of points is adjusted via "FFT size". To export octaves, use "x1;y1\nx2;y2;...". • Accelerometer connects to the headphone jack (measurement range from 5 Hz to 24000 Hz). • A stroboscope for an external accelerometer (the feature was proposed by Todd French from Los Angeles, California). • Bluetooth accelerometer. When converting acceleration into speed or displacement, at 0-5 Hz frequencies noise starts prevailing over vibration peaks, which is why such frequencies are disregarded when doing the conversion. Should vibration frequency exceed 50 Hz, the peak will be recorded at an incorrect frequency, and hence speed or displacement will not be calculated correctly. Unrealistically high speed or large displacement may be a sign of this kind of false frequency.

Your iPhone is a surprisingly capable vibration meter — when the app is honest about it. MeterWorks Vibrometer measures, records, and hands you your raw data: no subscription, no ads, no account, no tracking. MEASURE • Live readout with a big RMS value and a smooth real-time graph • All three axes plus magnitude, 100 Hz sampling, m/s² or g • Zero adjustment to cancel sensor offset before you measure • Selectable time window (10/30/60 s) and coupling tips for clean measurements RECORD & ANALYZE • Recordings with key metrics: RMS, peak, peak-to-peak, crest factor • Zoom, pan, and cursor in the recording graph — stats recalculated for the visible range • Pro: FFT spectrum with a peak list (dominant frequencies, rpm hint) YOUR DATA IS YOURS • Free: PNG export of any graph • Pro: clean CSV export of the full raw time series — spreadsheet-ready (comma or semicolon style), shared in seconds via Mail, Files, or AirDrop • Pro: multi-page PDF report with a statistics matrix across all axes, every graph, and the spectra — plus device info and a methodology footer FREE VS. PRO — NO SURPRISES The free version is a real instrument, not a teaser: live measurement, three recordings of 10 seconds each, full metrics, PNG export. The Pro unlock is a single one-time purchase — no subscription, ever. It removes the limits: unlimited recordings of any length, CSV raw-data export, FFT analysis, and the full PDF report. Buy it once, keep it forever, including future Pro features. WHAT THIS APP CANNOT DO — HONESTLY iPhone sensors measure reliably from roughly 0.1 to 50 Hz. That covers building and traffic vibration, washing machines, pumps, fans, and 3D printers. Bearing or gearbox diagnostics and certified measurements are beyond any smartphone — apps promising that are bluffing. The in-app page "Limits of this measurement" explains exactly what works, what doesn't, and why. TYPICAL USES Document construction vibration at your home · balance a washing machine · compare pumps and fans before and after maintenance · find 3D printer resonances · monitor sensitive cargo in transit NO SUBSCRIPTION. NO ADS. NO TRACKERS. All measurement data stays on your device. Nothing is uploaded, and nothing is locked into a proprietary format — the CSV you export is yours to keep, graph, and archive. Not a physics toolbox, not a sensor grab bag: one instrument, one job, done right. MeterWorks is a family of honest measurement apps: Sound Meter for your noise log, Teslameter for magnetic fields — just as honest, just as subscription-free.