The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Sep. 12, 1989

Filed:

Jul. 14, 1987
Applicant:
Inventors:

Koji Ichikawa, Kanagawa, JP;

Norikazu Soga, Kanagawa, JP;

Hirofumi Ohnishi, Kanagawa, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01F / ;
U.S. Cl.
CPC ...
7329 / ; 7386425 ; 7386434 ;
Abstract

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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