A method is provided for determining fluid momentum through one or more conduits. The method comprises the step of receiving an elongation signal from an elongation sensor indicating an elongation of the one or more conduits due to the flowing fluid. A momentum term is then calculated.

A capacitive fluid flow sensor and methods for measuring fluid flow are disclosed herein. An exemplary capacitive fluid flow sensor includes an airfoil having a flexible surface, and a capacitive sensor disposed within the airfoil. A capacitance of the capacitive sensor modulates as the flexible surface deflects in response to fluid flow. The fluid flow sensor may be secured within a cooled equipment enclosure, where the flexible surface of the airfoil deflects in response to fluid flow, such as airflow, within the cooled equipment enclosure.

A metering apparatus for determining a characteristic of a fluid, such as the volumetric flow rate, flowing through a non-linear section of a pipe is disclosed having a first strain gauge mountable to the non-linear section of the pipe offset from the bending neutral axis of the non-linear section of the pipe, to detect a bending force on the non-linear section of the pipe induced by the inertia of the fluid flowing through the pipe. A second strain gauge is mountable to the pipe disposed on the bending neutral axis of the non-linear section of the pipe, to detect at least one of the hoop strains, longitudinal strains and radial strains imparted on the pipe by the pressure of the fluid flowing through the pipe. A controller is configured to determine the mass flow rate of fluid flowing through the pipe based on the bending force determined by the first strain gauge and the at least one of the hoop strains, longitudinal strains and radial strains determined by the second strain gauge.

Cost effective pressure sensors for gas meters are described herein. In an example, responsive to an abnormal condition at an ultrasonic metrology unit of a gas meter, rates of pressure sensor operation are increased. In the example, the operations may include: measuring gas-environment pressure values; measuring contemporaneous air-environment pressure values; calculating pressure difference values of the gas-environment pressure values minus the contemporaneous air-environment pressure values; and comparing pressure difference values to one or more threshold values.

Methods and apparatus for determining mass flow rate of a CO.sub.2 rich stream using dielectric permittivity are described. A method herein measures a dielectric permittivity of a CO.sub.2 rich stream; determines a density of the CO.sub.2 rich stream from the measured dielectric permittivity; determines a viscosity of the CO.sub.2 rich stream from the measured dielectric permittivity; measures a pressure drop of the CO.sub.2 rich stream flowing through a flow restriction; and determines mass flow rate of the CO.sub.2 rich stream using the measured pressure drop, the determined density, and the determined viscosity.

Cost effective pressure sensors for gas meters are described herein. In an example, responsive to an abnormal condition at an ultrasonic metrology unit of a gas meter, rates of pressure sensor operation are increased. In the example, the operations may include: measuring gas-environment pressure values; measuring contemporaneous air-environment pressure values; calculating pressure difference values of the gas-environment pressure values minus the contemporaneous air-environment pressure values; and comparing pressure difference values to one or more threshold values.