Editing Alcohol Sensor Based on Gas-Sensitive Resistive Materials (section)

=== Dynamic Response Analysis ===
The Serial Plotter screenshots show that the system responded quickly after alcohol exposure. In the representative curves, the signal typically remained near the baseline for a period of time and then rose sharply once ethanol vapor reached the sensor. Figure 4(a) shows a typical rapid response at short distance, whereas Figure 4(b) shows the subsequent gradual decay. In several cases, the displayed value increased from around 15–20 to above 45 within only a short sequence of plotted points, indicating a fast practical response.

[[File:Figure4.png|thumb|center|500px|Figure 4. Representative dynamic behavior at 0 cm: (a) rapid signal rise after alcohol exposure; (b) gradual recovery after the response peak.]]

The recovery process was generally slower than the rising process. After the peak value was reached, the signal tended to decay more gradually, often with an extended tail instead of an immediate return to baseline. This is physically reasonable for a metal-oxide gas sensor because recovery depends on ethanol removal, desorption, and re-establishment of the surface equilibrium on the sensing layer.

Another dynamic feature visible in the plots is the presence of fluctuations and occasional secondary peaks after the initial response. These features suggest that the alcohol vapor inside the chamber was not perfectly uniform. Instead, the signal was likely affected by transient vapor transport, local mixing, and residual alcohol remaining in the chamber after the wipe had been introduced or moved. Overall, the dynamic measurements indicate that the system is suitable for real-time alarm applications, where practical threshold detection is more important than highly precise dynamic fitting.