Method for determining or monitoring a predetermined fill level, a phase boundary or a density of a medium

US8955377B2 · kind B2 · utility

Assignee

• ENDRESS+HAUSER GMBH+CO.KG · DE

Inventors

• Martin Hortenbach · Linkenheim-Hochstetten, DE
• Martin Urban · Bad Kötzting, DE
• Dietmar Frühauf · Bad Kötzting, DE
• Tobias Brengartner · Emmendingen, DE
• Frank Ruhnau · Neuenbürg, DE
• Michael Siegel · Los Angeles, US

Key dates

• Filing date: Apr 23, 2010
• Grant date: Feb 17, 2015
• Expiry date: Jun 7, 2031

Classification

• Technology area (CPC G): Physics
• CPC primary: G01F23/2967
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method and an apparatus for determining or monitoring a predetermined fill level, a phase boundary or a density of a medium in a container with an oscillatable unit. The oscillatable unit is placed at the height of the predetermined fill level and is excited to oscillate successively with discrete exciter frequencies following one another in a frequency scanning operation (sweep) within a predeterminable frequency band in the working range of the oscillatable unit. The corresponding oscillations of the oscillatable unit are received in the form of received signals; wherein that exciter frequency is ascertained in the frequency scanning operation, at which the oscillatable unit oscillates with an oscillation frequency, which has a predetermined phase shift between the transmission signal and the received signal; and wherein the transmitting/receiving unit excites the oscillatable unit to oscillate with the ascertained oscillation frequency.