Dielectric mixture composition sensor with compensation for mixture electrical conductivity

US6057693A · kind A · utility

Assignee

• Raytheon Company · US

Inventors

• J. Brian Murphy · Culver City, US
• John M. Brauninger · Los Angeles, US
• John McHardy · Westlake Village, US
• Clifford A. Megerle · Thousand Oaks, US
• Carl W. Townsend · Los Angeles, US

Key dates

• Filing date: Aug 27, 1996
• Grant date: May 2, 2000
• Expiry date: Aug 27, 2016

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N27/221
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The composition of an electrically conductive mixture, such as a mixture of gasoline and alcohol, is measured using a single measurement cell having a first electrode and a second electrode with a measurement space therebetween for receiving a specimen of the mixture. With a specimen of the mixture in the measurement space, the first electrode is alternatively connected to a reference discharge voltage, preferably ground, and to an applied voltage through a resistor. A first operational state encompasses the period when the first electrode is connected to the reference discharge voltage and a second operational state encompasses the period when the first electrode is connected to the applied voltage through the resistor. A first operational state peak voltage is measured during the first operational state, and a second operational state peak voltage is measured during the second operational state. The first operational state peak voltage and a preselected constant proper fraction of the second operational state peak voltage are summed to obtain a summed voltage output, which may be correlated to the composition of the mixture.