Fill-level measuring device

Patent metadata

Field	Value
Publication number	US-10168197-B2
Application number	US-201314431378-A
Country	US
Kind code	B2
Filing date	Aug 28, 2013
Priority date	Sep 26, 2012
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

A fill-level measuring device working according to the pulse radar principle for measuring a fill level of a fill substance in a container, comprising: a transmission system a pulse producing system, which, comprises, in each case, at least two measurements, for each measurement, produces a transmission signal composed of at least one microwave pulse periodically following one another, of center frequency predetermined for the particular measurement. The center frequencies of the transmission signals of at least two of the measurement are different from one another. An antenna connected to the transmission system, which sends the transmission signals into the container, and receives as received signals their signal fractions reflected in the container back in the direction of the antenna, and which has for different center frequencies different spatial radiation characteristics dependent on the center frequency of the transmission signals; and connected to the transmission system and the antenna, a signal processing system, which receives the received signals and evaluates such based on the center frequencies of the microwave pulses of the associated transmission signals and the center frequency dependence of the spatial radiation characteristic of the antenna.

First claim

The invention claimed is:

1. A fill-level measuring device working according to the pulse radar principle for measuring a fill level of a fill substance in a container, comprising:
a transmission system having a pulse producing system, connected to a control unit, which is embodied in such a manner that, in predetermined measuring cycles comprising, in each case, at least two measurements, for each measurement, it produces a transmission signal composed of microwave pulses of a center frequency predetermined for the particular measuring, wherein the center frequencies of the transmission signals of at least two of the measurings are different from one another;
an antenna connected to said transmission system, which sends the transmission signals into the container, and receives as received signals their signal fractions reflected in the container back in the direction of said antenna after a travel time dependent on the distance from the associated reflector of the fill-level measuring device, and which has for different center frequencies different spatial radiation characteristics dependent on the center frequency of the transmission signals; and
a signal processing system, connected to said transmission system and said antenna, which receives the received signals and evaluates such based on the center frequencies of the microwave pulses of the associated transmission signals and the center frequency dependence of the spatial radiation characteristic of the said antenna, wherein:
said antenna is a rod-shaped, and rectangular shaped hollow conductor with slots, which has an input fed by said transmission system, whose end lying opposite the input is terminally short circuited, terminated with a reflection free termination, or open, and which has a hollow conductor wall, which is provided with slot shaped slot like or fractal shaped cutouts, via which said antenna sends the transmission signals with a spatial radiation characteristic different for different center frequencies dependent on the positioning and dimensioning of said cutouts and the center frequencies of the supplied transmission signals; and
said antenna includes a focusing apparatus for focusing the transmission signals emerging from said antenna, a funnel-shaped or rectangular, hollow conductor segment arranged outwardly on the hollow conductor wall and enclosing all cutouts, a lens arranged outwardly on said hollow conductor wall, said lens comprising a dielectric lens or a magnetic lens, plates of one or more planar plies of a dielectric material applied outwardly on said cutouts, or other rectangular, hollow conductors embodied identically to the rectangular, hollow conductor and connected with said rectangular, hollow conductor to form a group of parallely amplitudes—and phase equally fed, rectangular, hollow conductors arranged together, parallel to one another, directly next to one another and perpendicular to the longitudinal axis of said rectangular, hollow conductor.

2. The fill-level measuring device as claimed in claim 1 , wherein:
said antenna is an antenna, especially a horn-, rod- or reflector antenna, which has a radiation characteristic, which includes a main lobe pointing in a main transmission direction and having an aperture angle rising with decreasing center frequency of the transmission signals.

3. A fill-level measuring device working according to the pulse radar principle for measuring a fill level of a fill substance in a container, comprising:
a transmission system having a pulse producing system, connected to a control unit, which is embodied in such a manner that, in predetermined measuring cycles comprising, in each case, at least two measurements, for each measurement, it produces a transmission signal composed of microwave pulses of a center frequency predetermined for the particular measuring, wherein the center frequencies of the transmission signals of at least two of the measurings are different from one another;
an antenna connected to said transmission system, which sends the transmission signals into the container, and receives as received signals their signal fractions reflected in the container back in the direction of said antenna after a travel time dependent on the distance from the associated reflector of the fill-level measuring device, and which has for different center frequencies different spatial radiation characteristics dependent on the center frequency of the transmission signals; and
a signal processing system, connected to said transmission system and said antenna, which receives the received signals and evaluates such based on the center frequencies of the microwave pulses of the associated transmission signals and the center frequency dependence of the spatial radiation characteristic of the said antenna, wherein:
said antenna is a rod-shaped and rectangular shaped hollow conductor with slots, which has an input fed by said transmission system, whose end lying opposite the input is terminally short circuited, terminated with a reflection free termination, or open, and which has a hollow conductor wall, which is provided with cutouts, especially with slot shaped, slot like or fractal shaped cutouts, via which said antenna sends the transmission signals with a spatial radiation characteristic different for different center frequencies dependent on the positioning and dimensioning of said cutouts and the center frequencies of the supplied transmission signals; and
the fill-level measuring device, wherein:
said cutouts are positioned and dimensioned in such a manner that the radiation characteristic of said antenna in the case of said closed end with a reflection free termination has a main transmission lobe and, in the case of said short-circuited or open end, two main transmission lobes extending symmetrically to the surface normal to said hollow conductor wall; and
an angle at which said main transmission lobes extend relative to the surface normal to said hollow conductor wall changes with the center frequency of the transmission signals.

Assignees

• Endress Hauser Gmbh Co Kg
• Endress Hauser Se Co Kg

Inventors

• Blodt Thomas

Classifications

• G01F23/284 Primary

  Electromagnetic waves · CPC title

• G01F22/00

  Methods or apparatus for measuring volume of fluids or fluent solid material, not otherwise provided for · CPC title