| 摘要 |
A liquid level detecting device comprises a vibrator for vibrating a sample vessel containing a sample solution, and a piezo-electric element provided on a suction member having an opening for sucking the sample solution. Changes in the output voltage of the piezo-electric element are read out as the suction member is moved vertically, contact of the lower end of the suction member with the sample solution is detected based on the changes in the output voltage, and the liquid level of the sample solution is detected. Or, the liquid level detecting device comprises a vibration transmitting plate for holding a nozzle member to a suction member, a vibrator for vibrating the nozzle member at a predetermined frequency, a frequency control circuit for changing the frequency of vibration, and a detector for detecting extreme values of the output voltage of the vibrator corresponding to changes in the frequency. The liquid level is detected based on changes in the extreme values.
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