Endress+hauser Gmbh+co.

Carsten Fitsch

Peter Gerst

Wolfgang Lubcke

Jurgen Lau

Stefen Burger

In measuring the level of a material in a container by a radar-based method the echo profile of the received microwaves is registered and a maximum of the echo profile established for determining the microwaves reflected by the material surface. To avoid false readings in the case of a double echo causing in the echo profile a double blip of two overlapping echo blips, consecutive maximum and minimum values of the slope of the echo profile and their distance values are determined starting from the established maximum in the direction towards smaller distances. The amplitude value of the echo profile assigned to the distance value located in the middle between the distance value of the first minimum slope and the distance value of the next maximum slope is used as the peak value of the first echo blip of the double blip decisive for level measuring.

Radar-based method of measuring the level of a 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.

Growing community of inventors

Bad Sackingen, Germany

Carsten Fitsch