METHOD FOR DETERMINING THE FILL STATE IN A TANK

摘要

The disclosure relates to a method for determining a level of a liquid in a tank with an ultrasonic fill state sensor and at least two reference surfaces for reflecting an ultrasonic wave transmitted by the ultrasonic fill state sensor. A first reference surface is arranged below a second reference surface. The method includes determining a first propagation speed of an ultrasonic wave to the first reference surface on a first measurement path and a second propagation speed from the first reference surface to the second reference surface on a second measurement path. The method also includes measuring a propagation time of an ultrasonic wave from the ultrasonic fill state sensor to a liquid level of the liquid in the tank, selecting the first propagation speed or the second propagation speed based on at least one selection criterion, and calculating a fill state using the propagation time measured.

主权项

1. A method for determining a level of a liquid in a tank with an ultrasonic level sensor and at least two reference surfaces for reflection of an ultrasonic wave that is emitted from the ultrasonic level sensor, wherein a first reference surface is disposed below a second reference surface, the method comprising the following steps:
a) determining a first propagation speed of an ultrasonic wave in the liquid over a first measuring distance from the ultrasonic level sensor to the first reference surface; b) determining a second propagation speed of an ultrasonic wave in the liquid over a second measuring distance from the first reference surface to the second reference surface; c) measuring a propagation time of an ultrasonic wave from the ultrasonic level sensor to a liquid level of the liquid in the tank; d) selecting the first propagation speed or the second propagation speed depending on at least one selection criterion; and e) computing a level with the propagation time measured in step c) and the propagation speed selected in step d).