Gas classification by an electronic-nose prototype based on a single gas sensor with novel temperature modulation

An electronic nose prototype based on the novel temperature-modulation technique is developed, where the heater voltage changes its amplitude and frequency periodically. The system comprises a sensor analog front end and a digital processing part including a heater voltage generator and a sensor data transmitter, where the digital part was implemented by a field programmable gate array. The fabricated prototype successfully generated the modulated heater waveform and synchronously acquired sensor responses at a sampling rate of 10 kHz. Whereby, sensor responses to the test gases of volatile organic compounds were collected. Gas classification was achieved with an accuracy of 99.6% based on the data obtained by the prototype, demonstrating the promising properties of the prototype as a compact and highly precise electronic nose.