‘Electronic Nose’ – Device identify the specific components of an odor and analyzes its chemical makeup.

An electronic nose is a device intended to detect odors or flavors. Over the last decade, “electronicsensing” or “e-sensing” technologies have undergone important developments from a technical and commercial point of view.

These device identify the specific components of an odor and analyzes its chemical makeup. An electronic nose consists of a mechanism for chemical detection, such as an array of electronic sensors, and a mechanism for pattern recognition, such as a neural network.

The basic concept of an electronic nose, or machine olfaction, is a measurement unit that generates complex multi-dimensional data for each measurement combined with a pattern recognition technique that interprets the complex data and relates it to a target value or class.

Electronic Sensor Technology, Inc. has developed an in-house center of innovation that has been continuously working on the advancements of zNose® to cater to the specific requirements of various industrial applications. While, the speed and accuracy of zNose® are the core features of Gas Chromatography technology, basis the portability and usability requirements, EST has launched four models of zNose®

4600A New Electronic Nose Using Acoustic Technology

Using ultra-high speed gas chromatography, zNose® is a powerful tool for identifying contraband of all kinds, hazardous industrial materials, improvised explosives, and flammable materials. Anything outside standard voc regulations is easily detected by zNose

In academic literature systems based on (for example) a mass-spectrometer in combination with pattern recognition are sometimes presented as an ‘electronic nose’ application or artificial olfaction. However, in this section only relatively low-cost sensor technologies are discussed which are in principle suitable for bench-top or portable devices are discussed.

The requirement that a multi-dimensional measurement signal is generated excludes single detection elements used for example PID meters. This is often overcome by using an array of broadly sensitive elements with different sensitivities to important chemical compounds. As an electronic nose device is frequently exposed to volatile chemicals arrays of potentiometric sensors are not useable.

The latter type are aimed at leak detection because they have a limited amount of reactive chemicals (the working principle is similar to a chemical battery) which is depleted when exposed to the target substances.

The technologies which are feasible for application are QMB/SAW, conducting polymers and metal-oxide sensors.
A QMB is a quartz crystal with a chemically active surface, usually a polymer. When gas molecules adsorb to the surface, the mass changes and the resonant frequency of the crystal shifts. These minute shifts need to be measured with high frequency electronics.