Research Article

Short-Time Fourier Transform and Decision Tree-Based Pattern Recognition for Gas Identification Using Temperature Modulated Microhotplate Gas Sensors

Figure 3

The typical output voltages and heating voltage. (a) The output voltages when the sensor is exposed in three analytes: 50 ppm carbon monoxide, 2000 ppm methane, and 30 ppm ethanol, respectively. (b) The heating voltage is sawtooth modulation waveform at 40 s periods.
(a)
(b)