| 摘要 |
PROBLEM TO BE SOLVED: To provide an ultrasonic liquid level meter for effectively preventing or suppressing a degradation in a S/N ratio of a liquid level detection due to a reverberation even if a plate thickness characteristic resonance frequency at the bottom of a vessel is adjacent to a sensor antiresonant point in a measurement system. SOLUTION: If the plate thickness is large at the bottom of the vessel, a band between the adjacent plate thickness characteristic resonance frequencies including an element resonance frequency (a sensor antiresonant point) possibly falling in a reverberation concern band is defined as a drive avoidance band. A drive frequency of an ultrasonic transmitting/receiving section is set outside the drive avoidance band. COPYRIGHT: (C)2010,JPO&INPIT |
