This page searches for the frequency a signal: something that repeats at regular intervals but remains invisible on a control chart.
The settings:
- Sampling interval : the time interval between two measurements. This interval defines the frequency scale; without it, the results are expressed in arbitrary units; ;
- Window : windowing applied before processing, to minimize edge artifacts; ;
- Frequency band (Hz)Â : restricts the analysis to a range; ;
- Top K and Minimum amplitude : Keep only the strongest lines.
The results show the spectrum, the table of rays, frequency, and amplitude, the signal rebuilt superimposed on the original, and the residue. Stingrays are exported.
đź’ˇ A clear trend is physically defined by its period: a spindle rotation, a conveyor rotation, a thermal control cycle, or a shift change. It is the residual error that indicates whether the model has captured the essence; if it remains structured, a periodicity has been missed.