Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Non Fire Yet But The Sensors Snap Into Action

07.12.2004


Russian researchers offer a fundamentally new approach to the development of gas sensors for fire-prevention detecting devices. In contrast to already known ones, these sensors allow to detect unerringly fire occurrence at its earliest stage. However, this is not a single advantage of the innovation or a sole field of application.



Moscow scientists - specialists of the Institute of Molecular Physics (Russian Research Center) “Kurchatov Institute” have managed to teach fire-prevention detecting devices to promptly and precisely catch the carbon monoxide occurrence in the air. The new device would not be deceived either by cigarette smoke, or by stange scents which sometimes make traditional fire alarm systems snap into action. No device in the world is equal to the new one in terms of sensitivity and selectivity.

Alexey Vasiliev, senior staff scientist, manager of work (Kurchatov Institute), narrated about new sensors at the international “Chemical sensors” conference, which took place in July in a Japanese “town of science” - Tsukuba - located not far from Tokyo.


The appearance of the sensors, the first experimental specimens of which were demonstrated by A.A. Vasiliev to all comers, had been preceded by extensive experimental and theoretical work. The authors suggested an absolutely new approach to development of sensors, the approach relating both to the sensors’ sensitive layer composition and their operating mode.

The point is that although the carbon oxide (CO - carbon monoxide) gas sensors have been known for quite a long time, their operation is not at all irreproachable. Principle of their operation is conventionally as follows: a layer of metal oxide, for example of tin or zinc, is the sensor. The determinate gas is sorbed on the oxide layer. Along with that, electroconductivity of the layer changes – it increases. That is the analytical response – the higher the conductivity of the sensitive layer gets, the higher the concentration of the sought gas is.

To increase the CO sensors selectivity, a catalyst – usually palladium – is introduced in the sensitive layer composition. When heated, the catalyst turns carbon monoxide into carbonic acid gas. This process, in its turn, affects the layer conductivity – therefore, these sensors are more sensitive, than the ones based simply on adsorption process.

The problem is that such sensors are easy to “deceive” – their readings are influenced by other gases as well, first of all by steam. And atmospheric humidity is known to be highly inconstant. That is why the fire safety systems are equipped with simplier sensors which are less sensitive but they snap into action “for sure” – when the room is already full of smoke or it is on fire, and the temperature exceeds all conceivable norms.

As for the sensors developed by the Moscow researchers, they would not be deceived either by steam or by any other gases, which impact the traditional sensors’ readings. The sensitive layer based on tin oxide with addition of palladium and platinum (the latter accelerates the process of carbon monoxide oxidation through to carbonic acid gas) allows to perform this process most efficiently.

The temperature condition suggested by the developers provides for two more invaluable advantages. Firstly, the sensor response increases particularly at the CO concentration being close to the maximum permissible concentration. Secondly, the researchers managed to select the temperature of operation in such a way that other gases on the catalyst simply do not have time to oxidize. Therefore, neither steam, nor hydrogen, nor methane or other carbohydrates “misleading” traditional sensors do affect the new sensors’ readings.

“Such sensors allow to detect occurrence of track concentrations of carbon monoxide at the initial stage of ignition, long before the fire appears as such, says Alexey Vasiliev. However, this is not their sole application. Sensors based on them may be used to identify the carbon monoxide concentration in motor exhausts.”

Sergey Komarov | alfa
Further information:
http://www.informnauka.ru

More articles from Physics and Astronomy:

nachricht Airborne thermometer to measure Arctic temperatures
11.01.2017 | Moscow Institute of Physics and Technology

nachricht Next-generation optics offer the widest real-time views of vast regions of the sun
11.01.2017 | New Jersey Institute of Technology

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Solar Collectors from Ultra-High Performance Concrete Combine Energy Efficiency and Aesthetics

16.01.2017 | Trade Fair News

3D scans for the automotive industry

16.01.2017 | Automotive Engineering

Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs

16.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>