Environmental control system fluid sensing system and method

US7350367B2 · kind B2 · utility

Assignee

• Visyx Technologies, Inc. · US

Inventors

• Leonid Matsiev · San Jose, US
• Oleg Kolosov · San Jose, US
• Mark Uhrich · Redwood City, US
• William Rust · Mountain View, US
• John Feland · San Jose, US
• John F. Varni · Campbell, US
• Blake Walker · Eugene, US

Key dates

• Filing date: Sep 27, 2004
• Grant date: Apr 1, 2008
• Expiry date: Apr 27, 2025

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2291/101
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A system for monitoring a fluid in an environmental control system includes a mechanical resonator positioned for contacting a thermal change fluid. In some embodiments, the mechanical resonator is positioned in a passage for containing the thermal change fluid. Suitable thermal change fluids include an R-134A refrigerant, a mineral oil, an ester lubricant or a mixture thereof; a superheated refrigerant; or an elevated pressure and elevated temperature vapor, an elevated pressure liquid, a reduced pressure liquid, a reduced pressure vapor and combinations thereof. The mechanical resonator can be a flexural resonator or a torsion resonator. In some embodiments, the mechanical resonator is a tuning fork resonator. Methods of the invention include monitoring a response of the mechanical resonator to the thermal change fluid. In some embodiments, at least a portion of the mechanical resonator is translated through the thermal change fluid and the response of the resonator to the fluid is monitored.