Calibration- and/or monitoring method for FMCW radar fill level measuring devices

US9581484B2 · kind B2 · utility

Assignee

• ENDRESS+HAUSER GMBH+CO.KG · DE

Inventors

• Winfried Mayer · Hobrechtsfelde, DE
• Manfred Eckert · Lauchringen, DE

Key dates

• Filing date: Mar 19, 2012
• Grant date: Feb 28, 2017
• Expiry date: Apr 21, 2033

Classification

• Technology area (CPC G): Physics
• CPC primary: G01F25/24
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method is based on measuring a distance to a reference reflector arranged at a known distance, in order to calibrate and/or monitor a coherent frequency modulation, continuous wave radar, fill-level measuring device, wherein the reference reflector can be reliably identified. To this end, a reference reflector executing oscillations toward the fill-level measuring device with an oscillation frequency is used, which is inserted in the beam path of periodically linearly frequency modulated transmission signals transmitted from the fill-level measuring device. The fill-level measuring device receives fractions of the transmission signals reflected back on reflectors in the container and records based on these received signals and their time correlation relative to the respectively associated transmission signal for each received signal an echo function, which shows the amplitudes of the received signal as a function of the associated position of the associated reflector. Based on the time change of a plurality of sequentially recorded echo functions and the oscillation frequency of the reference reflector, the position of the reference reflector in the echo functions is identified a…