LIQUID LEVEL MEASUREMENT DEVICE

• US 3,693,445 A
• Filed: 06/26/1970
• Issued: 09/26/1972
• Est. Priority Date: 06/26/1970
• Status: Expired due to Term

• Current Assignee: Sven J. Johnson
• Original Assignee: Sven J. Johnson
• Inventors: Johnson, Sven J.
• Primary Examiner(s): Prince, Louis R.
• Assistant Examiner(s): Shoon, Frederick
• Application Number:
  US05/050,192
• Time in Patent Office: 823 Days
• Field of Search: 73/29V,313
• US Class Current: 73/290.00V
• CPC Class Codes: G01F 23/2962 Measuring transit time of reflected waves
• CPC Class Codes: G01F 23/68 using electrically actuated indicating means
• CPC Class Codes: Y10S 367/908 Material level detection, e.g. liquid level

Abstract

A liquid level measurement device utilizes ultrasonics to determine the height of a liquid. The ultrasonic transducer is located at the bottom of the liquid container and within a porous or holey cylinder. Ultrasonic pulses are transmitted up the cylinder to a spherical float where they are reflected back to the transducer and sensed. The cylinder tends to minimize the spherical spread of the pulse wave. A timing system measures the time interval between the transmission and reception of the ultrasonic pulses by the transducer. The time interval measured is directly proportional to the height of the liquid and is electronically converted to an equivalent height.

Claims

1. In an apparatus for measuring the height of liquid, the combination comprising a transmitter coupled to an ultrasonic transducer, a movable float, confining means surrounding the float throughout its range of motion to limit the lateral excursion of said float, and a receiver with timing means coupled to said transducer and said transmitter;

wherein said ultrasonic transducer is positioned with relation to said confining means to direct ultrasonic pulses toward said float, and said receiver is positioned to receive echoes of said ultrasonic pulses from said float within said confining means;

together with means for confining the ultrasonic pulses to the portion of the medium within said first mentioned confining means.

2. In an apparatus for measuring the height of liquid as claimed in claim 1, said confining means being a cylinder having fluid communication means.

3. In an apparatus for measuring the height of liquid as claimed in claim 2, said fluid communication means comprising a plurality of apertures positioned in at least one wall of said cylinder to provide for fluid communication through said cylinder wall.

4. In an apparatus for measuring the height of liquid as claimed in claim 1, said float being spherical in form.