| 摘要 |
PURPOSE: To accurately measure fluid velocity from the time when a signal passes two separated points, by installing a transmitter oscillator generating a signal having a plurality of cycles or pulses which contain phase variation acting as a marker. CONSTITUTION: A transmitter oscillator 21 generates a signal having a plurality of cycles or pulses in which phase variation acting as a marker is contained. The signal is transferred to a first and a second transducers. The received signal is amplified by an amplifier 24, and then stored in a scanned capacitor array 25. The stored data act as a phase memory to a reference value which has passed a filter 27, and a phase detector 29 for obtaining phase variation, and further acts as an information storage source after phase variation detection by a microprocessor 31 is ended. The microprocessor 31 obtains the transit time on the basis of the data from voltage values stored in the capacitor array 25. |
