A PRESENTATION ON

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A PRESENTATION ON
ELECTRONIC NOSE
PRESENTED BY vivek gangwar ELECTRONICS
COMMUNICATION
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CONTENTS
INTRODUCTION SMELL ORGANS IN LIVING BEINGS
ARTIFICIAL SMELL TECHNIQUES WORKING PRINCIPLE
OF E NOSE VARIOUS TYPES OF SENSORS MORE ON
WORKING. RANGE OF APPLICATIONS CREDITS.
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INTRODUCTION
WHAT IS AN E NOSE? WHY E NOSE? WHAT IS
ODOUR? WHAT ARE VOCS? WHAT ARE RECEPTORS?
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ELECTRONIC NOSE Electronic nose or (e nose) is
a device that identifies the specific
Components of an odour and analyzes its chemical
makeup to Identify it. An e nose consists of
mechanism for identification of chemical
detection such as an array of electronic sensors
and a mechanism for pattern recognition
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ODOUR odour in a substance is due to VOCS or
volatile Organic compounds which evaporate and
get carried Away by air RECOGNITION
receptors in human nose act as binding sites
for VOCS these vocs are then processed by
brain and We recognise the smell.
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• MAIN COMPONENTS OF E NOSE
• SENSING SYSTEM
• PATTERN RECOGNITION SYSTEM
• SUB COMPONENTS
• SAMPLE DELIVERY SYSTEM
• DETECTION SYSTEM
• COMPUTING SYSTEM

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More on working

• 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
  global finger print analysis and provides results

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BLOCK DIAGRAM
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SCHEMATIC DIAGRAM
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• WORKING OF E NOSE
• In a typical e-nose, an air sample is pulled by a
  vacuum pump
• through a tube into a small chamber housing
  the electronic
• sensor array.The tube may be of plastic or
  stainless steel.
• A sample-handling unit exposes the sensors to
  the odorant,
• producing a transient response as the VOCs
  interact with the
• active material.
• The sensor response is recorded and delivered
• to the Signal-processing unit.
• Then a washing gas such as alcohol is applied to
  the array
• for a few seconds or a minute,so as to remove
  the odorant
• mixture from the active material.

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INTRODUCTION TO SENSORS A sensor is a device
which can respond to some properties of the
environment and transform the response into an
electric signal. The general working mechanism of
a sensor is illustrated by the following scheme
  In the field of sensors, the correct
definition of parameters is of paramount
importance because of these parameters allow
the diffusion of more reliable information among
researchers or sensor operators, allow a better
comprehension of the intrinsic behavior of the
sensors help to propose new standards, give
fundamental criteria for a sound evaluation of
different sensor performances.   The output
signal is the response of the sensor when the
sensitive material undergoes modification
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TYPES OF SENSORS E-nose is classified based on
the type of sensors used. 1. Conductivity
Sensors 2. Piezoelectric Sensors 3. FET gas
Sensors 4. Optical Sensors
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Conductivity sensors

• Metal oxide type
• Polymer type

• Both of which exhibit a change in resistance
  when exposed to volatile organic
• compounds.
• Metal oxide gas sensors can be subdivided into
• ? Thick film devices (depositing a paste of
  material between two electrodes)
• ? Thin film devices they use vapor deposition
  technologies in order to obtain a
• very thin film of metal oxide between two
  electrodes.

• Polymer Sensors
• Here the active material is a conducting
  polymer from such families as the
• polypyroles, thiophenes, indoles or furans.
  Changes in the conductivity of these
• materials occur as they are exposed to various
  types of chemicals, which bond with
• the polymer backbone.

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BASELINE RESISTANCE
All of the polymer films on a set of electrodes
(sensors) start out at a measured resistance,
their baseline resistance. If there has been no
change in the composition of the air, the films
stay at the baseline resistance and the percent
change is zero
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THE ELECTRONIC NOSE SMELLS SOMETHING
Each polymer changes its size, and therefore its
resistance, by a different amount, making a
pattern of the change
If a different compound had caused the air to
change, the pattern of the polymer films' change
would have been different
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• Optical Fiber Sensors
• These utilize glass fibers with a thin chemically
  active material coating on
• their sides or ends.
• A light source at a single frequency is used to
  interrogate the active
• materials which responds with the change in
  colour to the presence of VOCs.
• The active material contains chemically active
  fluorescent dyes immobilized
• in an Organic polymer matrix. As VOCs interact
  with it, the polarity of the
• fluorescent emission spectrum changes.
• Advantages Cheap and easy to fabricate. Arrays
  of fiber sensors have
• wide range of sensitivities. Differential
  measurement is possible to avoid
• common mode noise.
• Disadvantages Complexity of the measuring
  system.

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Range of applications

• It is used in research development laboratories
• It is used in quality control laboratories
• Its is used in process and production departments
  of various companies.
• able to detect tiny amounts of explosives

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In RD LABORATORIES

• Formulation or reformulation of products
• Benchmarking with competitive products
• Shelf life and stability studies
• Selection of raw materials
• Packaging interaction effects
• Simplification of consumer preference test

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In Quality Control laboratories

• Conformity of raw materials, intermediate and
  final products
• Batch to batch consistency
• Detection of contamination, spoilage,
  adulteration
• Origin or vendor selection
• Monitoring of storage conditions.

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In process and production departments for

• Measurement and comparison of the effects of
  manufacturing process
• on products
• Following-up cleaning in place process efficiency
• Scale-up monitoring
• Managing raw material variability
• Comparison with a reference product
• Cleaning in place monitoring.

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THANK YOU
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QUERIES?