Development of a sonar for finding gas compositions

 Gases are needed for several processing needs; such as in the form of reactants, or carriers, or as media in research or industry. Different types of gases are in use for such applications, classified as toxic, chemically reactive, inflammable, or noble, etc. However, detecting a gas composition in a given gas mixture in static or in an on line manner (during the processing) is rather a difficult problem, and needs high tech equipments or time consuming techniques, such as gas chromatography, mass spectrometry or some chemical reactants based methods, etc. Solid state gas sensors based on thin films, or thin film based instruments are now available but they are application specific and may take some time (response time) to provide the result, and may remain dead (recovery time) for some time, in case needed to be used for another application. We have developed a gas sensor locally, based on the physical properties of the gas media. The system can measure gas composition of a gas mixture in the static or in dynamic mode (on line) in the background of some standard gas and provide results for separate sample, or on continuous basis. The method is non invasive (does not interact with the gas media), and can be used for any type of gas mixtures. It uses the mechanical pulse echo technique and provides reliable information on gas composition in almost entire range (1 to 99%). The resolution depends upon the molecular weight of the sample gas with respect to that of the background gas. In some specific cases such as light gases, or super-heavy gases the resolution can be much better. The system has been used for monitoring composition of large number of binary gas mixtures, prepared by Mass Flow Controller (MFC) / rotameter combination. We have measured several gases such as CO2, H2 , O2, SO2, SF6 etc., mixed with different background gases.

About Dr. Jagdish Chandra Vyas :

Dr. J. C. Vyas {M.Sc. (Phys.), Univ., of Rajasthan, Jaipur, Ph.D. (Bombay (now Mumbai) University)} was teaching physics to graduate students at the Govt. Degree College, Nathadwara (Raj.), for a short period, and subsequently joined BARC through training school (23rd batch) at Mumbai. Over the years he was involved in research and development activities in several fields, such as silicon solar cells (for space applications), growth of single crystal materials for second harmonic generation (SHG) using lasers and other applications, thin film based high temperature super-conducting materials. He has handling experience of several techniques such as Molecular Beam Epitaxy, Pulsed Laser deposition, vacuum systems of different types, etc. He has published more than seventy five technical papers, as individual or in collaboration with others, in national and international journals, as well as a book chapter in the Science and technology of ancient India, published by Vijnan Bharati Mumbai. He was also a member of the editorial board of this book.

He has interest in science popularization, and delivered talks from research level (in Univ Depts) down to high school standards, and on popular science for general audience. He has interest in the Indian philosophy and ancient sciences. He may be contacted by Email at the following address: j.c.vyas@gmail.com