Capacitance based mass metering for cryogenic fluids

✍ Scribed by Mark A. Nurge; Robert Youngquist; Deron Walters

• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 320 KB
• Volume: 43
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/s0011-2275(03)00127-9

✦ Synopsis

This paper describes a method for measuring the mass of cryogenic fluids in on-board rocket propellant tanks or ground storage tanks. Linear approximations to the Clausius-Mossotti relationship serve as the foundation for a capacitance based mass sensor, regardless of fluid density stratification or tank shape. Sensor design considerations are presented along with the experimental results for a capacitance based mass gage tested in liquid nitrogen. This test data is shown to be consistent with theory resulting in a demonstrated mass measurement accuracy of ±0.75% and a deviation from linearity of less than ±0.30% of full scale mass. Theoretical accuracies are also shown to be ±0.73% for hydrogen and ±1.39% for oxygen for a select range of pressures and temperatures.