A survey on odour detection sensors

Human beings possess six highly efficient sensory system such as vision, hearing, touch, taste and smell. Many of these sensory systems are artificially replicated to provide intelligence to the machines. This paper reviews the various techniques and instruments that can be used to design a human olfactory system, which can be used in different applications. The odour detection systems can be broadly classified into four categories such as gas sensors, bio-sensors, gas chromatography systems and hybrid systems. Other common odour detection instruments like electronic noses (E-noses), mass spectrometers (MS), differential optical absorption spectrometers (DOAS) are also reviewed in this paper. The selection of any odour detection technique is influenced by several factors like on-field deployability, odour detection and classification capabilities, sensitivity of the instruments and sensitivity of the instruments to the air matrices. Among all the possible detection methods, Electronic nose is having advanced capabilities as compared to other instruments. The presence of interference noise act as a major hindrance for the efficiency of the odour detection devices. Integration of gas chromatography along with interference filters can provide an increased accuracy in the odour detection.