| 摘要 |
A distance measurement device uses ultrasound transmitted along a variable fluid path and then interferometrically compared with the measurement echo. The variable fluid path can be replaced by an electronic device to reduce cost. The electronic reference contains a comparator stage (3) connected to the ultrasonic device (1) on one side and, via a time element (4) and a further comparator (5), to a pulse stage (6) to which it is also directly connected. The pulse circuit drives an oscillator (7) connected to a mixer-separator (9) via a damping element (8). The probe (12) is connected to the measuring device (1) via the mixer-separator (9) and a decoupler (11). |
