Tittmann B.

A method and apparatus are described for monitoring gas vibrations within a container or pipe under pressure. An acoustic transducer is used to apply an oscillating force to the surface of the vessel. The frequency of the transducer is swept through a range which causes resonant vibrations in the gas. A receiving transducer measures the amplitude of the resultant vibration at the vessel surface and reveals the resonant frequency of the gas at peaks in the amplitude of the sweep. The resonant frequency obtained depends upon the composition of the gas, its pressure and temperature and the geometry of the container. These relationships can be predetermined empirically so that the pressure inside the vessel can be calculated when the composition of the gas, its temperature and geometry of the confining vessel are known. The output of the receiver is fed into a computer which is programmed to calculate the pressure based upon these predetermined relationships which are stored in the computer. The method is described for a spherical steel vessel filled with Helium gas. Good agreement is found between the analytical predictions and the measurements over a range of pressures. The results appear to hold promise for a monitor of gas pressure in containers, pipes and pressure vessels.