Method for determining filling level in container filled with liquid used in water separator, involves arranging sound transmitter and sound receiver in area of containers above liquid surface

摘要

The method involves arranging a sound transmitter (22) and a sound receiver (23) in an area of the containers (15,17) above a liquid surface (F). The excitation frequency of the sound transmitter is changed, where the stationary waves (W1,W2) are identified by the sound receiver. A distance between the sound transmitter and the liquid surface are determined from the frequency of the stationary waves and the wavelength.