Vibration analysis vs NVH

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.

Does your vehicle have a vibration problem? NVH takes the guesswork out of diagnosing it! Just follow the road test instructions in the tutorial, and the NVH app can automatically detect the type of vibration your vehicle is experiencing. - There are 14 types of vibrations: - Tire speed-related (3 types) - Driveshaft speed-related (3 types) - Engine speed-related (7 types) - Electric Motor Speed Related (1 type) - Each type of vibration has unique causes. A vibration type is not the same thing as a vibration source. There are many possible causes (sources) for each vibration type. Just follow the app's diagnostic steps to identify the source of vibration. - There are almost 300 possible causes of vibration concerns in today's vehicles. - Tire speed-related (77 Possible Causes) - Driveshaft speed-related (123 Possible Causes) - Engine speed-related (76 Possible Causes) - Electric Motor Speed Related (Several Causes) More than "Just an App," this is a tool for professional service technicians and anyone with a vibration concern on their vehicle. KEY FEATURES: - QUICK, ACCURATE, AND PRECISE: The NVH App can be set up and ready to begin diagnosis in as little as 30 seconds! - VIBRATION DIAGNOSIS: Place or mount your device against a solid surface in your vehicle, and the internal sensors will measure and analyze your vehicle's vibration problem. - LIVE RESULTS: Watch one of three different displays that show you live measurements of your vibration in various ways to ensure you have all the information you need. - MULTI-PART ANALYSIS: - AUTOMATIC: Not sure how to interpret your results? NVH will analyze your road test for you and tell you which type of vibration problem your vehicle has. - TOTALS: Want to get into the numbers yourself? NVH shows you statistics for each type of vibration detected and breaks them down by vehicle speed to give you even more information. - PDF REPORT: print, email, or save a PDF diagnostic report showing all the analysis details. - RECORD: Record your road test and watch it again in real-time, or pause and go through it step by step. - SHARE: Want another field service engineer, mechanic, or friend to see your test and give their opinion? Export your recordings to an NVH file to import them into their device and view your recordings and their analyses. You can also print or send a PDF report detailing the recording analysis. - VEHICLE DATABASE: NVH has an extensive database of 45,184 vehicles to choose from, so that you can pick your vehicle and go! Can't find your vehicle in the database? Not a problem! You can manually enter your vehicle's information and save it for future use. To see a list of supported vehicles in the NVH vehicle database or what information you will need to know about your vehicle if it is not in the database, visit http://www.vibratesoftware.com/nvh/database.htm. - DIAGNOSTIC HELP AND VIDEOS: Whether you are a seasoned field service engineer, experienced technician, or a self-made mechanic, NVH's comprehensive diagnostic help file has something for everyone. Read through detailed instructions and information accompanied by hundreds of photos and dozens of videos. With over 28 years of vibration diagnostic expertise built into the troubleshooting steps, you will be in good hands. - SUPPLEMENTARY TOOLS: NVH contains a suite of extra tools to help with various automotive tasks: - Measure driveshaft angles - Check the accuracy of your speedometer - Measure raw vibration frequencies and amplitudes OPTIONAL BLUETOOTH OBD-II DLC INTERFACES: - OBDLink MX+ - Nexiq Blue-Link 2 These tools will read the engine RPM directly from the vehicle and use it for engine speed-related vibration diagnosis. NOTE: This application is intended to be used by a passenger in a vehicle, not the driver. You assume total responsibility and risk from using this application.