An intelligent detector based on temperature modulation of a gas sensor with a digital signal processor

An intelligent detector based on a hot-plate gas sensor and a digital signal processor (DSP) is presented. The work comprises sensor measurements and gas identification with a pattern recognition (PARC) system along with a systematic verification of both stages, thanks to clustering validity methods and performance tests. Commercial silicon micromachined tin-oxide sensors have been used to capture dynamic measurements modulating the sensor heater at different temperatures, waveforms and frequencies. Feature extraction is based on the spectral and transient analysis of the sensor output signals. The PARC systems are based on self-organizing maps (SOM) and recent variations of these well-known neural networks. The proposed hardware is in charge of the whole system: the sensor temperature modulation and signal processing.