Endress+hauser Gmbh+co.

Other

Endress + Hauser Gmbh + Co. Kg

Wolfgang Lubcke

Johanngeorg Otto

Peter Gerst

Winfried Maier

Roland M&uuml;ller

Thomas Malzahn

Carsten Fitsch

Jurgen Lau

Jean-Gyl Capt

A continuous measurement of the level of contents in a container is effected by a level measuring device functioning in accordance with the transit time principle by means of waves transmitted from a position located above the highest possible contents level onto the surface of the material in the container. A measuring circuit determines the contents level from the transit time of the useful echo reflected from the material surface. In addition, one or more limit sensors are located at the container, each of which furnishes a signal indicating whether the contents level is above or below a level to be monitored by the limit sensor and which is situated between the minimum and maximum contents levels of the container. The measuring circuit receives the output signals of all limit sensors and uses these output signals to check and eventually to correct the contents level measured value determined by the level measuring device. In particular, the measuring result furnished by the level measuring device can be compared with an exact contents level value every time the contents level reaches the level monitored by a limit sensor whereby the level indication of the limit sensor changes its status. In certain cases, a single limit sensor is sufficient for this purpose, which monitors a contents level which is regularly exceeded or undershot in the normal use of the container.

Arrangement for measuring the level of contents in a container

A continuous measurement of the level of contents in a container is effected by a level measuring device functionong in accordance with the transit time principle by means of waves transmitted from a position located above the highest possible contents level onto the surface of the material in the container. A measuring circuit determines the contents level from the transit time of the useful echo reflected from the material surface. In addition, one or more limit sensors are located at the container, each of which furnishes a signal indicating whether the contents level is above or below a level to be monitored by the limit sensor and which is situated between the minimum and maximum contents levels of the container. The measuring circuit receives the output signals of all limit sensors and uses these output signals to check and eventually to correct the contents level measured value determined by the level measuring device. In particular, the measuring result furnished by the level measuring device can be compared with an exact contents level value every time the contents level reaches the level monitored by a limit sensor whereby the level indication of the limit sensor changes its status. In certain cases, a single limit sensor is sufficient for this purpose, which monitors a contents level which is regularly exceeded or undershot in the normal use of the container.

Measuring instrument having two pairs of lines connected to two indentical pairs of terminals, via which signal current flows through one pair and supply current flows through the other pair

The invention relates to an apparatus for determining the filling level of a filling material in a container having a signal production unit which produces measurement signals, having at least one antenna which transmits the measurement signals in the direction of the surface of the filling material and which receives the measurement signals reflected on the surface of the filling material, and having a control/evaluation unit which uses the delay time of the measurement signals to determine the filling level of the filling material in the container. The apparatus allows a filling level measurement device, which operates on the delay-time principle, to be mounted on a container in a cost-effective and simple manner. An opening is provided in the upper region of one sidewall of the container, and in that the at least one antenna is positioned in this opening with the antenna being arranged and configured such that the measurement signals are emitted essentially in the direction of the surface of the filling material and such that the measurement signals reflected on the surface of the filling material are received by the at least one antenna.

Apparatus for determining the filling level of a filling material in a container

For measuring the level of a material in a container on the basis of the radar principle, microwaves are radiated downwards and reflected microwaves received by means of the antenna of a ranging device arranged above the highest level anticipated. In the normal measuring operation the received microwaves are evaluated in the distance range up to empty distance corresponding to the distance of the antenna from the bottom of the container for determining the echo waves reflected from the surface of the material, for measuring the transit time of the echo waves and for computing the distance of the material surface from the antenna of the ranging device from the measured transit time. In order to reliably detect the empty condition of a container having a curved bottom, despite the multiple reflections of the microwaves reflected from the container bottom, when no echo waves are detected in the distance range up to the empty distance, the evaluation is done in an enlarged distance range and any echo waves detected in the enlarged distance range beyond the empty distance are assigned to the empty distance.

Radar-based method of measuring the level of a material in a container

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Steinen, Germany

Wolfgang Lubcke