Sensor, in particular for measuring the viscosity and density of a medium

US6269686A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Dietmar Hahn · Gerlingen, DE
• Gottfried Flik · Leonberg, DE
• Falk Herrmann · Fairport, US

Key dates

• Filing date: Feb 4, 1999
• Grant date: Aug 7, 2001
• Expiry date: Feb 4, 2019

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2009/008
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A sensor which has a bending reed and a piezoelectric resonator. Due to excitation by the piezoelectric resonator, the bending reed can be excited to vibration in a measurable medium. In this context, the vibration frequency and the damping of the bending reed are a function of the density and the viscosity, respectively, of the measurable medium. This can be measured by a piezoresistive element, and thus the density and viscosity of the measurable medium are ascertained.