Acoustic principle

Filter systems designed by acoustical principles. Figure 13-lD and 13-lE. 

Sensors based on acoustic principles are suitable for in-situ-measurements of gas concentration in industrial processes. They can even be used for aggressive media [1]. The velocity of sound - in the following formula marked as VOS - is taken as the characteristic criterion. 

Up to now, sensors using this parameter have not been taken into consideration, as they are generally not selective. Water for instance is traceable in air because its velocity of sound is significantly higher. The VOS of carbon dioxide is just around 1/3 the VOS of air. In a mixture of air, water and C02 none of the compounds can be quantified. As the VOS of carbon monoxide is similar to that of air, CO cannot be quantifiedby this method either. Hence, sensors based on acoustic principles cannot be taken into consideration neither for the measurement of single species in a flue gas flow nor for the identification of fuel gases. 

Ebeling, K.J. Statistical properties of random wave fields in Physical Acoustics Principles and Methods. New York Academic Press, 1984. 

W. P. Mason, Physical Acoustics. Principles and Methods, Academic Press, New York, London, 1964. 

H.G. Flynn, Physics of acoustic cavitation in liquids, in W.P. Mason (Ed.), Physical Acoustics Principles and Methods, Vol. I, Part B, Academic Press, New York, 1964, pp. 57-172. 

Chapter 2 introduces the acoustic principles common to all the devices ... 

The simplest model of these waves is one based on acoustic principles. Assume that the earth can be treated as an acoustic medium and the influence of variations in density can be ignored. In this case the propagation of seismic waves in the earth can be described by the acoustic wave equation ... 

Ballato A 0977) Doubly rotated thickness mode plate vibrators. In Mason WP, Thurston RN (eds) Physical acoustics principles and methods, vol XIII. Academic, New York... 

Mason WP (ed) (1%5) Physical acoustics- principles and methods, vol. II- part A, properties of gases, liquids, and solutions. Academic, New York/London... 

R. S. Marvin, and J. E. McKinney in Physical Acoustics Principles and Methods, voLH, P-B,... 

The Violin, Its Physical and Acoustic Principles, by Paolo Peterlongo, a Crescendo Book, Taplinger Publishing Company, New York, 1979. 

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