Method for determining the current filling level of a liquid in a container

Abstract

The invention relates to a method for determining the current filling level of a liquid, preferably a calibrating, quality control, or cleaning fluid, or waste water, in a container, for example of an analyzer, where an immersion pipe is dipped into the liquid in the container to be filled or drained. The immersion pipe is connected to a pumping device via a tube system. The pressure p in the tube system is measured and increased, starting from the ambient pressure p, until a first discontinuous pressure change occurs at pressure pdue to the liquid column in the immersion pipe being forced out of the pipe, and/or the pressure p in the tube system is decreased until the liquid column in the immersion pipe reaches a change in cross-section of the immersion pipe, which change is situated above the maximum filling level of the liquid, such that a second discontinuous pressure change occurs at pressure pdue to the liquid column reaching the change in cross-section. The pressure difference between ambient pressure pand the pressure por pat one of the two pressure discontinuities or the time tor tuntil one of the two pressure discontinuities is reached, is recorded and used to determine the current filling level of the container.