Invention Grant
- Patent Title: Capacitive liquid-level sensor
- Patent Title (中): 电容液位传感器
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Application No.: US13054645Application Date: 2009-07-21
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Publication No.: US08474315B2Publication Date: 2013-07-02
- Inventor: Mikihiro Ohshima , Motoki Ogata , Yoshinori Takashima , Takeshi Kashiwagi
- Applicant: Mikihiro Ohshima , Motoki Ogata , Yoshinori Takashima , Takeshi Kashiwagi
- Applicant Address: JP Osaka
- Assignee: Panasonic Corporation
- Current Assignee: Panasonic Corporation
- Current Assignee Address: JP Osaka
- Agency: Pearne & Gordon LLP
- Priority: JP2008-188111 20080722; JP2008-290546 20081113; JP2008-290547 20081113; JP2008-290548 20081113; JP2009-048780 20090303
- International Application: PCT/JP2009/003397 WO 20090721
- International Announcement: WO2010/010683 WO 20100128
- Main IPC: G01F23/26
- IPC: G01F23/26

Abstract:
In a liquid level sensor according to the present invention, a first detecting electrode being always in a liquid to be measured, a second detecting electrode which measures a level of the liquid to be measured, and a third detecting electrode being always out of the liquid to be measured are arranged, an operation of charging capacitor 45 for a time being in proportion to a ratio of a length of a part of the second detecting electrode in the liquid to be measured to a total length of the second detecting electrode and an operation of discharging the electric charge of the capacitor for a time being in proportion to a ratio of a length of a part of the second detecting electrode being out of the liquid to be measured to the total length of the second detecting electrode is repeated. With this configuration, the liquid level can be precisely detected without arranging a complex operational device even though a dielectric constant or a temperature of the liquid to be measured changes.
Public/Granted literature
- US20110113878A1 LIQUID-LEVEL SENSOR Public/Granted day:2011-05-19
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