Method for measuring the filling level of a filling material in a container

Abstract

The invention relates to a method for measuring the filling level (L) of a filling material (2) in a container, which method is based on the pulse radar method. The method according to the invention is distinguished in that the repetition frequency (fpuls) of the microwave pulses is not constant but rather is controlled in accordance with the propagation time (t) in such a way that the repetitionfrequency (fpuls) is increased when the propagation time (t) becomes shorter and is decreased when the propagation time (t) becomes longer. According to the invention, the filling level (L) is therefore determined not on the basis of the measured propagation time (t) but rather on the basis of the arising repetition frequency (fpuls). Therefore, the invention provides a pulse-radar-based method for filling-level measurement that can be realized with reduced circuit complexity in comparison with the classic pulse radar method and with the FMCW method. The reason for this is that only the repetition frequency must be sensed in order to perform filling-level measurement. Said pulse-radar-based method requires neither a complex analog evaluation circuit nor highly accurate time measurement, incontrast with the classic pulse radar method. Complex digital data processing, which is required in the FMCW-based method for filling-level measurement, is also dispensed with.

Description

technical field [0001] The invention relates to a method for measuring the fill level of a filling substance in a container by means of microwave pulses, and to a fill-level measuring device suitable for carrying out this method. Background technique [0002] In automation technology, especially in process automation technology, field devices are often used for recording and / or influencing process variables. Field devices for recording process variables are sensors integrated in, for example, level measuring devices, flow measuring devices, pressure and temperature measuring devices, pH and redox potential measuring devices, conductivity measuring devices, etc., which record the corresponding Process variables, level, flow, pressure, temperature, pH, redox potential and conductivity. Field devices for influencing process variables are actuators, such as, for example, valves or pumps, via which the flow of a liquid in a pipe section or the fill level in a container can be ch...

AI Technical Summary

Problems solved by technology

A disadvantage of this method, however, is its complex circuitry, in which case, above all, the time extension and evaluation of the envelope curve is considerable

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