| 摘要 |
In a level indicator (12), in particular for fuel tanks (10) of motor vehicles, a transmitter (13) induces flexional waves (17) in a sonic conductor (11). The level(h)-dependent feedback on the sonic field dimensions in the sonic conductor (11) at the transmitter (13) or in its vicinity (sonic immittance) is used to determine measurement values. For that purpose, the changes in cross impedance are evaluated. A linear measurement gradient is obtained that can be clearly associated with a level (h) within a half-angle of the change in phase angle. |
