Non-intrusive pressure/multipurpose sensor and method

US6301973A · kind A · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventor

• William C. Smith · Jessup, US

Key dates

• Filing date: Apr 30, 1999
• Grant date: Oct 16, 2001
• Expiry date: Apr 30, 2019

Classification

• Technology area (CPC G): Physics
• CPC primary: G01L11/04
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Method and apparatus are provided for determining pressure using a non-intrusive sensor that is easily attachable to the plumbing of a pressurized system. A bent mode implementation and a hoop mode implementation of the invention are disclosed. Each of these implementations is able to non-intrusively measure pressure while fluid is flowing. As well, each implementation may be used to measure mass flow rate simultaneously with pressure. An ultra low noise control system is provided for making pressure measurements during gas flow. The control system includes two tunable digital bandpass filters with center frequencies that are responsive to a clock frequency. The clock frequency is divided by a factor of N to produce a driving vibrational signal for resonating a metal sensor section.