| 摘要 |
The invention relates to a method and a device used in a tank (1) for holding liquid substances and equipped with a radar level-measuring apparatus (2). From the tank walls (1), residue of the substance are removed by means of at least one jet of liquid (3a1, 3b1) that is directable in space according to a predetermined pattern. In accordance with the method and based on the radar level-measuring apparatus (2) derived indication of the jet of liquid's (3a1, 3b1) passage through the radar beam (2a) of the radar level-measuring apparatus (2), at least the frequency of rotation of the jet of liquid (3a1, 3b1) in the tank (1) is determined. The invention related device comprises means (5) for determining, from the radar level-measuring apparatus (2, 4) signal, the frequency of rotation of the jet of liquid (3a1, 3b1) in the tank (1). |
