Abstract: A cryogenic density and mass-flow measurement system incorporating a high-speed microprocessor-based cryogenic fluid density instrumentation that is based on the rigorous application of the molecular dielectric theory, using a dielectric susceptibility function in the application of the Clausinus-Mossotti formula, and the introduction of the quantitation of a new susceptibility parameter k which serves to bridge the gap between the theoretically rigorous molecular dielectric equation and the macroscopic dielectric equation. The operating principle is formulated on a differential dielectric measurement approach with a new algorithm which provides for automatic adjustments for polarizability and stray capacitance changes. High precision digital density measurement is achieved over a wide range of cryogenic fluid states ranging from supercritical through subcritical to the slush phase.

Abstract: Flowmeter apparatus and method for obtaining accurate measurement of fluid flow, not only in the turbulent flow range, but also in the laminar and transitional flow ranges by compensation of the meter reading. The meter reading is also compensated for change in viscosity of the fluid flowing through the meter. The compensation for flow range is based on the best-fit straight line approach obtained by matching straight line segments to the quantity versus frequency output curve throughout the laminar and transitional ranges, and compensating the flowmeter reading in accordance with the shape of the straight line segments. The compensation for change in kinematic viscosity of the fluid is added to the flowmeter output in accordance with the temperature-viscosity relationship for the fluid and in accordance with a ratio of compensation factors between the actual fluid and a reference fluid.