LPG/CNG LEAKAGE ALARM is a product developed by Sensor & Actuator Section, the Central Glass & Ceramic Research Institute, Kolkata. The product works on the following principle of operation: The sensor materials are primarily based on n-type semi-conducting oxides (like tin dioxide, zinc oxide) and their resistance values drop drastically in the presence of reducing gases (like methane, hydrogen, carbon monoxide) owing to the reaction of the latter with the meta stable adsorbed oxygen species on the surface of the semiconductor.
The change in resistance is the signature of the presence of a trace amount of leaked gas in the ambient, says Amarnath Sen, scientist, the Central Glass & Ceramic Research Institute. Dr. H.S. Maiti, Director, CGCRI, is the coordinator of the project. The institute’s scientists and technical workers are involved in the development work.
The estimated cost of the sensor unit should be less than Rs 500. Regarding the launching of the product, negotiations have been going on with prospective entrepreneurs. A few vendors are available across the globe, which supply gas sensor heads. However, using CGCRI's technology, the product can be launched at a much lower price.
Incidentally, CGCRI has patented a technology of gas sensor which can detect LPG/CNG even in the presence of a trace amount of highly reactive volatile organic compounds. Sensor & Actuator Section of CGCRI has also developed methane and carbon monoxide sensors jointly with the Central Mining Research Institute, Dhanbad.
Semi-conductor sensors are quite cheap, rugged and can last up to 10 years. The product finds applications in homes, hotels, restaurants, automobiles, gas storing and refilling stations, hospitals, office buildings, factories, mines, research laboratories, train dining cars or any other indoor space where large number of people congregate or poisoning possibilities exist.
Specifications of
Developed Sensors
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LPG/CNG Sensor
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Pocket Module
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Size
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8 cm dia and 2.5 cm idth
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Weight
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~ 50 g
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Power consumption
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1 Watt
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Minimum detection limit
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500 ppm
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Sensitivity [(Ra
– Rg)/ Ra]
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> 85%
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Sensor resistance (in air
at 350oC)
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50-70 kW
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Response Time
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10 sec
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Recovery Time
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1 min
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