Abstract: There is provided a method of, and apparatus for, measuring the mass of a gas under pressure using a piezoelectric oscillator. The gas is contained within a pressure vessel (100) having a fixed internal volume (V) and the piezoelectric oscillator (202) is immersed in the gas within the pressure vessel (100). The method comprises: a) utilizing said piezoelectric oscillator (202) to measure the density of the gas within the high-pressure vessel (100); b) determining, from the density measurement and from the internal volume (V) of said pressure vessel, the mass of the gas within the pressure vessel (100). By providing such a method, the true contents (i.e. mass) of fluid in a pressure vessel such as a cylinder can be measured directly without the need to compensate for factors such as temperature or compressibility. This allows a determination of mass through direct derivation from the density of the gas in the cylinder, reducing the need for additional sensors or complex calculations to be performed.

Abstract: There is provided a method of and apparatus for, measuring the mass of a gas under pressure using a piezoelectric oscillator. The gas is contained within a pressure vessel (100) having a fixed internal volume (V) and the piezoelectric oscillator (202) is immersed in the gas within the pressure vessel (100). The method comprises: a) utilising said piezoelectric oscillator (202) to measure the density of the gas within the high-pressure vessel (100); b) determining, from the density measurement and from the internal volume (V) of said pressure vessel, the mass of the gas within the pressure vessel (100). By providing such a method, the true contents (i.e. mass) of fluid in a pressure vessel such as a cylinder can be measured directly without the need to compensate for factors such as temperature or compressibility. This allows a determination of mass through direct derivation from the density of the gas in the cylinder, reducing the need for additional sensors or complex calculations to be performed.

Abstract: The present invention is directed to fluid containment vessels having an internal surface coated with an organic coating comprising one or more poly(arylene ethers) polymers and methods for making and using same. When applied to the internal surfaces of fluid containment vessels, the coating reduces the potential for corrosion and mitigates contamination of the chemicals stored therein.