Vibration is a true vibration spectrum analyzer using the built in accelerometers and gyroscope inside the iPod Touch and the iPhone and starting with version 3.x it can sample the built in microphone and the Digiducer professional quality external USB accelerometer. It acquires and displays time series data, optionally removes DC bias, applies a Hamming window and performs an FFT on each channel to produce frequency spectra. The 3-channel accelerometer has a sensitivity of approximately 0.02g and a range of ±2g making the iPhone and iPod Touch sensitive enough to analyze the vibration of most moving machinery.
In many applications Vibration can be an excellent portable alternative to a commercial spectrum analyzer. In predictive maintenance applications Vibration can help identify bearing defects, shaft misalignment, imbalance, and structural resonant frequencies. Vibration is also useful for monitoring the acceleration of part and material handling equipment.
The software is flexible and easy to use. It was written to emulate the familiar oscilloscope based spectrum analyzer. Sample rate and sample delay are easily adjustable and the user can select the length of the data acquisition and the vertical scale used for the display. Once the settings are configured simply press the sample button on the device or on your Apple Watch. When a test is complete the resulting data can be emailed to your desktop computer for documentation purposes.
• Sample the built in accelerometer or gyroscope, the internal Microphone or the professional Digiducer USB accelerometer. Additional Digiducer accelerometer features can be enabled via in-app purchase.
• Adjustable sample rate from 10Hz to 100Hz for the internal sensors and 1 kHz to 16 kHz for the internal microphone and the Digiducer accelerometer (with in-app purchase)
• Trigger sampling and review settings using the Apple Watch companion app.
• Auto repeat and auto save allow data to be taken over extremely long periods of time.
• Selectable data length from 256 to 4096 samples
• Variable start delay from 0 to 20 seconds
• Adjustable vertical scale for time series data
• DC Remove option to get rid of the gravity vector
• Switchable Hamming window for frequency analysis
• Frequency data plotted as Linear-Linear, Log-Log, Log-Linear and Linear-Log
• Computes rms and peak levels for each channel and for all three channels combined
• Document your results by taking screen snapshots and syncing them to your computer or sending a CSV formatted email with the time and frequency data to your computer or saving data locally and downloading the data with iTunes
• Turn on and off individual frequency plots
• Calibrate the internal accelerometers and examine and edit the calibration data
• Optional sounds to mark the start and stop of data acquisition
• Data inspectors and zoom
• Triggering off one or more accelerometer channels or microphone input.
• Frequency data averaging and peak hold.
Further development and additional features are planned. Please use the email links in the program to request new features and report any problems.
• Added support for The Modal Shop 485B39 Digital ICP two channel USB input module
• Fixed Triggering to work properly with external input devices. See manual for instructions
Ratings and Reviews
Bought this app over 5 years ago because the vibration sensor we were using in the lab wasn’t quite working for our need. We wanted to know the vibration noise source for a piece of equipment we were designing. With this app, we were able to determine the peak frequencies, and therefore the source of our noise. Impressed the whole team with the fact that it was an iPhone that solved the mystery. Ever since then this app has been a fun toy at home.
Mostly good, but possibly flawed
I was impressed to find such a technically advanced app. However when I use the microphone input on an iPhone, the sound frequencies appear to be represented in the spectrum view at twice their actual frequency. I haven't put it on the bench yet, but when I calibrate a whistle or sing tone with another app, the Cleartune app, the tones are represented in this Vibration app at twice the frequency registered in the Cleartune app. I have used the Cleartune app to practice various pieces of music and it seems spot on.
I work in an industry where I have occasion to use some pretty high tech vibration analysis on prototype systems, so I was interested in what this could do. So far, I'm fairly impressed with the results. I like that you can get csv output, I like that there is some degree of sensitivity control, and I like the calibration. My complaints, such as they are, are divided into technical capabilities and interface. For the interface, I guess I don't like the way the settings screens are arranged. You get one set of controls from the time display, one from the frequency display, and another from the iPhone's settings app. You can't even toggle between the first two settings screens! And the buttons are not quite professional looking. The bottom three buttons look clunky, and the acquisition time and vertical scale button groups are poorly animated during the page flip animation. I also think there's a cleaner, more intuitive way to do the toggling between acceleration, velocity, and displacement. Seriously, I had no idea what was going on with those until I read the help pages.
Technically, I want higher frequency in the data. I set to 100hz, and I can only see about 25hz in the upper end of the frequency plots.
Also, the app hangs once in a while and has to be reset.
Thanks for doing everything else right.
- Bruce Truax
- 13.2 MB
- Requires iOS 9.3 or later. Compatible with iPhone, iPad, and iPod touch.
- Age Rating
- Rated 4+
- © Diffraction Limited Design LLC
- In-App Purchases
- Enable full Digiducer functionality $14.99
With Family Sharing set up, up to six family members can use this app.