Is that vibration random noise or a real rhythm?
A wobbly line can be a sum of clean rhythms in disguise. The FFT rewrites your series as frequencies, and the magnitudes tell you which rhythms are really there and how strong each one is.
Analytics Starter Statistics free
After you install, this is the model to open.
Find the Hidden Vibration Frequencies
- In your spreadsheet, click the Sortia icon in the strip of icons down the right-hand edge. No strip? Click the arrow at the bottom-right to open it. You can also use Extensions, then Sortia, then Open Sortia.
- Click Start from a template and put that name in the search box.
- Pick the card with that name and click Load this template. It arrives on a new tab with real numbers already in it.
The answer
Two spikes stand out of the magnitude column and nothing else does:
- Frequency 2
- 32.0 magnitude
- Frequency 5
- 12.0 magnitude
- Everything else
- ~0
Mechanics read spikes as signatures: a twice-per-window beat might be shaft imbalance, the faster tone bearing wear. Read only the first half of the output, the mirror-image spikes above n/2 repeat the same information, and frequency 0 is just the sum of the series. Hourly traffic, daily orders, sensor hum: any rhythm hunt on 8 to 4096 points works.
The model
Sixteen evenly spaced readings from a vibration sensor on a motor, built from a strong component repeating twice across the window plus a weaker one repeating five times.
| Samples | 16 readings (power of 2 required) |
| Magnitude per frequency | calculated |
Once it is in your sheet
- The model arrives with real numbers in it and runs as it stands, so you can press the button first and understand it second.
- Change the numbers to yours. The sheet marks which cells are inputs and which hold formulas, and most labels carry a note explaining the row.
- Press the run button at the bottom of the panel. It is labeled for the tool you are in, and the result lands on its own tab, with a written reading of it beside the figures.
Never used Google Sheets? Start here goes the whole way, in seven steps, and assumes nothing.
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Every model like this one, and the method behind them: Statistics in Google Sheets.