Patent ID: 8616053
Filing Date: 2013-12-31
Classification: G01F

Abstract:
1. A method of monitoring a fill level of a liquid in a liquid container, which comprises: providing a liquid container with a heated thermocouple mounted in the container at a given installation height level and an associated unheated thermocouple; inferring that the liquid level has sunk below the given installation height level of the heated thermocouple from a measured temperature difference between the heated thermocouple and the unheated thermocouple; continuously monitoring a temporal profile of the temperature difference for a significant increase within a time interval, which occurs before a respective evaluation time point, of a duration that is previously fixed; outputting an alarm signal as soon as a change in the temperature difference within the time interval reaches or exceeds a previously fixed limit value; thereby ascertaining a sequence of temperature differences over a large number of periodically sequential measurement time points, wherein the differences between the last ascertained sequence element and all of its predecessors, the measurement time points of which fall within a time interval of pre-specified length, are formed at an evaluation time point, and the alarm signal is output as soon as at least one of the differences reaches or exceeds a previously fixed limit value.