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

Figure 2

Experimental setup for data acquisition. (a) The gas mixture is injected to the testing chamber at a constant flow rate, with gas components and concentrations controlled by the MFCs. The gas sensors are placed in the testing chamber, and the data is recorded by computer. (b) The measurement circuit. Each gas sensor has two resisters. is acting as both heater and thermometer, and is the resistance of the gas sensing film. is the heating voltage for temperature modulation. and are constants and is recorded as the sensor data.

(a)

(b)