An electronic nose is an instrument to detect odors and/or flavors and was developed in order to mimic human olfaction. The instrument consists of three modules which essentially fulfill the following tasks - head space sampling, odor/flavor sensing, and pattern recognition.
Electronic noses include three major parts: a sample delivery system, a detection system, a computing system.
• The sample delivery system enables the generation of the headspace (volatile compounds) of a sample. The system then injects this headspace into the detection system of the electronic nose. The sample delivery system is essential to guarantee constant operating conditions.
• The detection or sensory system, which consists of a sensor array/set, is the "reactive" part of the instrument. When in contact with volatile compounds, the sensors react, which means they experience a change of electrical properties.
The more commonly used sensors for electronic noses include
o metal–oxide–semiconductor
o conducting polymers
o quartz crystal microbalance
o surface acoustic wave
• The computing system works to combine the responses of all of the sensors and helps identify the odor/flavor. Commonly used data interpretation systems for the analysis of responses from the detection system include artificial neural network (ANN), fuzzy logic, pattern recognition modules, etc.
As a first step, an electronic nose needs to be trained with qualified samples so as to build a database of reference. Then the instrument can recognize new samples by comparing signal pattern generated by a volatile compound to those contained in its database.
Electronic nose instruments are used by research and development laboratories, quality control laboratories and process & production departments for various purposes. This also has possible future applications in the fields of health and security.
References:
http://en.wikipedia.org/wiki/Electronic_nose
Electronic noses include three major parts: a sample delivery system, a detection system, a computing system.
• The sample delivery system enables the generation of the headspace (volatile compounds) of a sample. The system then injects this headspace into the detection system of the electronic nose. The sample delivery system is essential to guarantee constant operating conditions.
• The detection or sensory system, which consists of a sensor array/set, is the "reactive" part of the instrument. When in contact with volatile compounds, the sensors react, which means they experience a change of electrical properties.
The more commonly used sensors for electronic noses include
o metal–oxide–semiconductor
o conducting polymers
o quartz crystal microbalance
o surface acoustic wave
• The computing system works to combine the responses of all of the sensors and helps identify the odor/flavor. Commonly used data interpretation systems for the analysis of responses from the detection system include artificial neural network (ANN), fuzzy logic, pattern recognition modules, etc.
As a first step, an electronic nose needs to be trained with qualified samples so as to build a database of reference. Then the instrument can recognize new samples by comparing signal pattern generated by a volatile compound to those contained in its database.
Electronic nose instruments are used by research and development laboratories, quality control laboratories and process & production departments for various purposes. This also has possible future applications in the fields of health and security.
References:
http://en.wikipedia.org/wiki/Electronic_nose
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