of electronic nose technologies have come through advances in The invention of many new e-nose sensor types and arrays, based on. Abstract—The "electronic nose" is a relatively new tool that may be used for safety, quality, or process monitoring, accomplishing in a few minutes procedures . ABSTRACT. Electronic/artificial noses are being developed as systems for the automated detection and classification of odors, vapors, and gases. An electronic .
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Electronic/artificial noses are being developed as systems for the automated detection and classification of odors, vapors, and gases. An electronic nose is generally composed of a chemical sensing system (e.g., sensor array or spectrometer) and a pattern recognition system (e.g. PDF | Electronic noses are customized devices employed to detect and to identify gaseous mixtures, even to give the concentration of the atmosphere. Electronic nose. What is electronic nose? Application areas. Wireless Sensor Networks Based Electronic-nose used for monitoring and improving air.
Published on Dec 12, Abstract In an ever-developing world, where electronic devices are duplicating every other sense of perception, the sense of smell is lagging behind. Yet, recently, there has been an urgent increase in the need for detecting odours, to replace the human job of sensing and quantification. Some of the most important applications fall in the category where human beings cannot afford to risk smelling the substance. Other important applications are continuous monitoring, medical applications, etc. These applications allow man to perform tasks that were once considered impossible. The fast paced technology has helped develop sophisticated devices that have brought the electronic nose to miniature sizes and advanced capabilities.
It has also to be remarked a psychological difference, in human beings, between the two groups. Indeed the information from the physical senses can be adequately elaborated, verbally expressed, firmly memorized and fully communicated. On the contrary chemical information, coming from nose and tongue, are surrounded by vagueness and this is reflected in the poor description and memorization capacity in reporting olfactory and tasting experiences.
Chemical information is of primary importance for the major part of the animals; for many of them, indeed, chemistry is the unique realm of which they are concerned, while for human beings evolution has enhanced about exclusively the physical interfaces, leaving little care of the chemical interface, if we exclude unconscious acquisition and side behaviours.
For these intrinsic difficulties toward the understanding of the nature of these senses for many years only sporadic research on the possibility of fabricating artificial olfactory systems were performed. Only at the end of the eighties a new and promising approach was introduced. It was based on the assumption that an array of non-selective chemical sensors, matched with a suitable data processing method, could mimic the functions of olfaction.
In the past decade, electronic nose instrumentation has generated much interest internationally for its potential to solve a wide variety of problems in fragrance and cosmetics production, food and beverages manufacturing, chemical engineering, environmental monitoring, and more recently, medical diagnostics and bioprocesses.
Several dozen companies are now designing and selling electronic nose units globally for a wide variety of expanding markets.
An electronic nose is a machine that is designed to detect and discriminate among complex odours using a sensor array. The sensor array of consists of broadly tuned non-specific sensors that are treated with a variety of odour-sensitive biological or chemical materials. An odour stimulus generates a characteristic fingerprint or smell-print from the sensor array. Patterns or fingerprints from known odours are used to construct a database and train a pattern recognition system so that unknown odours can subsequently be classified and identified.
Thus, electronic nose instruments are comprised of hardware components to collect and transport odours to the sensor array - as well as electronic circuitry to digitise and stored the sensor responses for signal processing.
Principle of E-nose Mimicking the nose is a challenging task. The human nose can smell 10, different odour molecules mixed in air. Odour in a substance is due to certain volatile organic compounds VOCs , which easily evaporate and get carried by an air stream. An e-nose can smell and estimate odours quickly though it has little or no resemblance to the human nose. A human nose has receptors, which serve as binding sites for VOCs.
A receptor is just a molecular structure on the surface of the nerve cell to which an odorous molecule with the right shape binds. The receptor and the binding molecule fit exactly as in a key and lock arrangement. These odour-sensing nerve cells line the upper part of the cavity in the human nose. Once an odour molecule binds to a receptor, a chain reaction follows which ultimately transmits an electrical signal to the brain.
A specific odour of coffee or wine is usually caused not by one, but a mixture of hundreds of organic compounds. So, the brain has a mammoth task of processing signals received from the nerve cells originating from the nose, to identify the nature of smell. The exact working of the brain in processing these signals is yet to be fully understood. The ability of an electronic nose to rapidly discriminate between slight variations in complex mixtures makes the techniques ideal for on-line process diagnostics and screening across a wide range of application areas.
Thus, electronic nose instruments are comprised of hardware components to collect and transport odours to the sensor array — as well as electronic circuitry to digitise and stored the sensor responses for signal processing. The two main components of an electronic nose are the sensing system and the automated pattern recognition system. The sensing system can be an array of several different sensing elements e.
Each chemical vapour presented to the sensor array produces a signature or pattern characteristic of the vapour. By presenting many different chemicals to the sensor array, a database of signatures is built up. This database of labelled signatures is used to train the pattern recognition system.
Next, different pattern recognition techniques are presented to enhance the performance of chemical sensors. Then biological systems are considered as a possible blue-print for chemical sensing. The biology can be employed either to understand the way insects locate odorant sources, or to understand the signal processing neural pathways.
Next is a discussion of some of the new types of electronic noses; namely, a fast GC column with a SAW detector and a micromechanical sensor. Finally, the important issues of sampling technologies and the design of the microfluidic systems are considered.
In particular, the use of pre-concentrators and solid phase micro extractors to boost the vapour concentration before it is introduced to the chemical sensor or electronic nose. Skip to main content Skip to table of contents.
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Papers Table of contents 20 papers About About these proceedings Table of contents Search within book. Front Matter Pages i-xvii. Pages Polymer Electronics for Explosives Detection.
Optical Microsensor Arrays for Explosives Detection. Electrochemical Sensing of Nitroaromatic Explosives.