19-07-2014, 03:23 PM
BANASTHALI UNIVERSITY RAJASTHAN
[attachment=66022]
INTRODUCTION
An electronic nose is a device that identifies the specific components of an odor and analyzes its chemical makeup to find it.
It consists of certain mechanisms such as an array of electronic sensors for chemical detection and artificial neural network for pattern recognition
PREVIOUS WORK DONE
E-nose was first suggested by K. Persaud and George Dodd of Warwick University in 1982.
Then afterwards in 1988, another professor of this university named Julian Gardner conducted his research on this.
It then came into popular use after 1989.
Since then, development of sensor array-based instruments has been actively pursued in Asia, Europe and North America
CONTD
The sample delivery system enables the generation of the headspace (volatile compounds) of a sample.
The detection system, which consists of a sensor set, is the “reactive” part of the instrument. When in contact with volatile compounds, the sensors experience a change of electrical properties. Each sensor is sensitive to all volatile molecules but each in their specific way.
The computing system works to combine the responses of all the sensors which represent the input for the data treatment; it then performs analysis and provides results.
CONTD
OPTICAL SENSORS
These utilize glass fibers with a chemically active material coating on their sides or ends.
A light source is used to interrogate the active material which responds with the change in color to the presence of VOCs.
The active material contains chemically active fluorescent dyes. As the VOCs interact with it, the color of the fluorescent dye changes, hence lead to detection.
CYRANOSE 320
The Cyranose 320 is a handheld “electronic nose” developed by Cyrano Sciences of Pasadena, California in 2000.
Applications researched using the Cyranose 320 includes the detection of COPD, and other medical conditions as well as industrial applications generally related to quality control or contamination detection
APPLICATIONS
In environmental monitoring:
For identification of volatile organic compounds in air, water and soil samples.
For environmental protection.
In quality control laboratories:
Conformity of raw material, intermediate and final products.
Detection of contamination, spoilage and
adulteration.
Monitoring of storage conditions.
ADVANTAGES OVER BIO NOSE
The human sniffers are costly as compared to
e-nose. Also detection of hazardous gases by them is not possible.
E-nose has wide range of sensitivity.
Results obtained by e-nose are fast and more accurate.
It is well- suited for repetitive or boring tasks.
It can also detect substances which are not detected by our human nose, like mercury.
CHALLENGES INVOLVED
E-nose can only identify a standard set of odors which is stored in its database.
Though it is effective but still it can’t mimic the complex human olfactory system exactly.
They also have shorter lifetime because of the sensors employed in them.
Moreover, e-noses available in market are not economical.
In the field of crime prevention
The ability of the electronic nose to detect odorless chemicals makes it ideal for use in the police force, such as to detect drug odors despite other airborne odors capable of confusing police dogs. However this is unlikely in the mean time as the cost of the electronic nose is too great and until its price drops significantly it is unlikely to happen.
It may also be used as a bomb detection method in airports. Through careful placement of several or more electronic noses and effective computer systems you could triangulate the location of bombs to within a few meters of their location in less than a few seconds
CONCLUSION
An electronic nose is a system created to mimic the functioning of human nose.
Since the whole working is automatic, it can also be used by non specialists.
Although it has several advantages, yet it is still far from the selectivity provided by a human nose.
Basically, it is a tool provided to overcome the shortcomings of human nose thus giving us more fast and accurate results.
Future developments in the use of advanced sensor arrays and the development of adaptive artificial neural networking techniques will lead to superior electronic noses.
[attachment=66022]
INTRODUCTION
An electronic nose is a device that identifies the specific components of an odor and analyzes its chemical makeup to find it.
It consists of certain mechanisms such as an array of electronic sensors for chemical detection and artificial neural network for pattern recognition
PREVIOUS WORK DONE
E-nose was first suggested by K. Persaud and George Dodd of Warwick University in 1982.
Then afterwards in 1988, another professor of this university named Julian Gardner conducted his research on this.
It then came into popular use after 1989.
Since then, development of sensor array-based instruments has been actively pursued in Asia, Europe and North America
CONTD
The sample delivery system enables the generation of the headspace (volatile compounds) of a sample.
The detection system, which consists of a sensor set, is the “reactive” part of the instrument. When in contact with volatile compounds, the sensors experience a change of electrical properties. Each sensor is sensitive to all volatile molecules but each in their specific way.
The computing system works to combine the responses of all the sensors which represent the input for the data treatment; it then performs analysis and provides results.
CONTD
OPTICAL SENSORS
These utilize glass fibers with a chemically active material coating on their sides or ends.
A light source is used to interrogate the active material which responds with the change in color to the presence of VOCs.
The active material contains chemically active fluorescent dyes. As the VOCs interact with it, the color of the fluorescent dye changes, hence lead to detection.
CYRANOSE 320
The Cyranose 320 is a handheld “electronic nose” developed by Cyrano Sciences of Pasadena, California in 2000.
Applications researched using the Cyranose 320 includes the detection of COPD, and other medical conditions as well as industrial applications generally related to quality control or contamination detection
APPLICATIONS
In environmental monitoring:
For identification of volatile organic compounds in air, water and soil samples.
For environmental protection.
In quality control laboratories:
Conformity of raw material, intermediate and final products.
Detection of contamination, spoilage and
adulteration.
Monitoring of storage conditions.
ADVANTAGES OVER BIO NOSE
The human sniffers are costly as compared to
e-nose. Also detection of hazardous gases by them is not possible.
E-nose has wide range of sensitivity.
Results obtained by e-nose are fast and more accurate.
It is well- suited for repetitive or boring tasks.
It can also detect substances which are not detected by our human nose, like mercury.
CHALLENGES INVOLVED
E-nose can only identify a standard set of odors which is stored in its database.
Though it is effective but still it can’t mimic the complex human olfactory system exactly.
They also have shorter lifetime because of the sensors employed in them.
Moreover, e-noses available in market are not economical.
In the field of crime prevention
The ability of the electronic nose to detect odorless chemicals makes it ideal for use in the police force, such as to detect drug odors despite other airborne odors capable of confusing police dogs. However this is unlikely in the mean time as the cost of the electronic nose is too great and until its price drops significantly it is unlikely to happen.
It may also be used as a bomb detection method in airports. Through careful placement of several or more electronic noses and effective computer systems you could triangulate the location of bombs to within a few meters of their location in less than a few seconds
CONCLUSION
An electronic nose is a system created to mimic the functioning of human nose.
Since the whole working is automatic, it can also be used by non specialists.
Although it has several advantages, yet it is still far from the selectivity provided by a human nose.
Basically, it is a tool provided to overcome the shortcomings of human nose thus giving us more fast and accurate results.
Future developments in the use of advanced sensor arrays and the development of adaptive artificial neural networking techniques will lead to superior electronic noses.