Engine RPM for Android

11 things about Engine RPM

1. After setting the the number of cylinders and whether the engine is a 2-stroke or 4-stroke engine, the app can work with any internal combustion engine, from diesel tractors to aircraft engines to motorcycles to chainsaws.

2. Engine RPM listens to the sound of a running engine and uses advanced signal processing algorithms to extract the frequency of that sound and calculate the RPM.

3. The analysis requires a clear sound from the engine without excessive interference from extraneous sounds.

4. For this reason, and because of the need for adjusting the expected RPM range, this app should not be considered a drop-in replacement for an operational tachometer.

5. Setup options include update periods from 93 milliseconds to 1.5 seconds, one to 12 cylinders, 2-stroke or 4-stroke, low-pass filtering, and signal clipping.

6. A real-time graph of the autocorrelation graph is displayed to help in troubleshooting and adjusting the expected RPM range.

7. Do not expect to read the RPM of an engine while other things are making too much noise at the same time.

8. To use the app you must set an expected RPM range to guide the analysis algorithms to the correct RPM.

9. Measure the RPM of an engine by analyzing the sound it makes.

10. The overall RPM range is 400 to 90,000 RPM (although at any one time, the operational range is typically +/- 30% around a nominal expected RPM).

11. It cannot read the RPM of an engine that is rapidly accelerating.