Vibration analysis vs Vibroscope

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.

"Vibroscope" is a powerful vibration analysis tool that uses the iPhone's acceleration sensor to measure various vibrations in real time. It allows you to monitor and visualize very low frequency vibrations that are inaudible to the human ear. This app intuitively detects acceleration amounts and displays the two-axial coordinates in the horizontal direction and the time-axis waveform in the vertical direction. It can measure by determining the horizontal or vertical direction to suit the attitude of the iPhone automatically, so as to be available on the floor and desk or handheld. "Vibroscope" is also equipped with FFT analyzer that can analyze the frequency components of very low frequency vibrations. The measurement data can also be saved as a log file, so you can use it as a vibration data logger. Application Examples: - Analysis of the amount of acceleration and frequency components of the floor and walls during car traffic. - Measurement of howling vibration of audio equipment, etc. - Detection of acceleration and vibration of trains and automobiles. - Body balance check (horizontal body shaking detection). - Measurement of vibration acceleration during earthquakes, etc. (displayed value x 100 [GAL]) Features: - Measurement of vibrations (Main): acceleration values (m/s/s) - Real-time display: the horizontal direction (X-Y) - 2-axis vector plane graph, the vertical direction (Z) - the time-varying graph. - Display scale switching of vibration acceleration graph (Linear/Log): Linear - linear scale display, Log - logarithmic scale display. - 3-axis composite acceleration display (Compo) - Peak level value display (Peak) - Switching of acceleration display (Instant/Average): Instant - instantaneous acceleration, Average - average acceleration per second. - Scaling of measurement display range - FFT analysis for 3-axis directional and composite acceleration, with peak frequency (FFT) - FFT graph display control (Axes/Axis-1/Axis-2) - Switching of sensor sampling period (Slow/Fast): slow, fast - Axis direction (Axis): Swapping the axis direction on the graph display during operation. - Measurement timer function: 1 sec to 1 hour - Start delay timer function: 0 - 20 sec - Reference level setting in FFT mode: 1e-6m/s/s, or 1e-5m/s/s - Snapshot of the measurement screen (Snap): Capture the measurement results and Timestamp to "Photos". - Data Logger: X-axis, Y-axis, Z-axis, saved in a text file (UTF8). It saves the measurement data, timestamp to LOG file. Important settings: - At the time of the first access to Photos after installing the app, you will be asked permission to access them from the iOS system. If you did not enable this setting on this time, it cannot be access from the app by privacy restrictions of the iOS. Please enable slide switch of the app in the access permission of the iOS setting, "Settings > Privacy & Security > Photos". - This app does not support to the background operation, so it needs to set on "Never" in the iOS setting, "Settings > General > Auto-Lock" for a long-time operation. Notes: - In general, there is variation and accuracy error by individual terminals and sensor devices of the iPhone, so this app does not recommend the use in the formal measurement. It is also possible that the accuracy error will accumulate if the vibration is too large, it may not be appropriate to display the measured value. - While driving a car or operating machinery, please do not use this app for safety. - The logarithmic scale graph displays very small numerical value, so it may be affected by noise and temperature error in your environment or time fluctuation of sensor calibration. - Log data can be transferred from an iOS device to a Mac or PC using the iTunes File Sharing feature. MacOS Catalina and later can share files between an iOS device and a Mac using the Finder. Please visit our iOS app support page for more information on this app.