What is Electronic Nose Technology | Electronic Nose Sensor

This page covers e-nose or Electronic Nose technology. It mentions different electronic Nose sensors, comparison between Biological Nose and e-nose (Electronic Nose), applications of e-nose etc.

The electronic device which identifies odour of specific components and analyzes its chemical composition is known as electronic nose or e-nose. The name has been given due to its similarities with the biological nose.

Following is the block diagram of electronic nose technology. As shown it consists of three main parts or modules or sub-systems viz. sample delivery system, detection system and computing system.

Let us see the working of the electronic nose technology device:

• Step-1:First air sample is taken inside by pump which is passed through the tube into small chamber. This chamber is composed of array of electronic sensors.

• Volatile organic compounds in the sample interact with active material surface of sensor. As a result transient response is produced.

• After some time steady state response is attained. This is sent to Signal Processing Unit.

• A washing gas (e.g. vapour of alcohol) is applied to array for some time (about 1 minute). This will remove odourant mixture from surface as well as active material of the sensor.

• Finally reference gas is subjected to array in order to prepare it for next new measurement.

electronic nose device

The figure is taken from wikipedia commons. It depicts electronic nose device model Cyranose 320 from Sensigent California, USA.
For further information contact sales@sensigent.com or
Visit website www.sensigent.com

Electronic Nose Sensors

Following are the types of electronic nose sensors widely used:

Piezoelectric Sensor: Absorption of gas molecules on surface of polymer results into changes in the mass. This changes in mass produces change in resonant frequency of crystal. This is directly proportional to concentration of test material.

Conductivity Sensor: Absorption of gas molecules causes changes in the conductivity. This changes in conductivity is proportional to total volatile organic compounds absorbed.

SAW Sensor: This type of sensor relies on modulation of SAW (Surface Acoustic Waves) to sense physical phenomenon.

Refer Sensor basics and types➤.

Difference between Biological nose and e-nose

Following table mentions comparison between Biological Nose and e-nose (Electronic Nose).

Biological nose e-nose
Inhaling Pump
Olfactory epithelium Sensors
Mucus Filter
Enzymatic Proteins Reaction
Binding with proteins Interaction
Nerve Impulses Circuitry and Neutral Network
Cell membrane depolarised Signal

Applications of Electronic Nose

Following are the applications of Electronic Nose:
• Medical diagnosis and health monitoring for example, respiratory diseases diagnosis, cancer detection, urinary tract infections etc.
• Environmental monitoring for example, detection of oil leaks, testing ground water, testing household odours, air quality monitoring etc.
• Applications in food industry for example, analysis of fruit ripening etc.

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