# US 2019/0170559 A1 · Ultrasonic fluid measurement probe with ultrasonically welded base cap > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0170559 A1 - Document ID: US20190170559A1 - Status: Published application - Kind: A1 - Application number: 15/833,129 - Filed: 2017-12-06 - Published: 2019-06-06 - Earliest claimed: 2017-12-06 - Assignees: The Boeing Company - Applicants: The Boeing Company - Inventors: Sigvard Johann Wahlin - Web page: https://patentgrep.com/patent/US20190170559A1 ## CPC - G01F 23/2962: Measuring transit time of reflected waves - G01F 23/296: Acoustic waves - G01F 15/14: Casings, e.g. of special material - G01F: MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME ## Abstract An apparatus and method of measuring a level of fluid in a container and of enhancing reliability of an ultrasonic fluid measurement probe. A base comprises a transducer chamber, wherein the transducer chamber comprises a transducer chamber floor, a transducer chamber edge, and transducer chamber walls extending from the transducer chamber floor to the transducer chamber edge. An ultrasonic transducer is attached to the transducer chamber floor. A cap is welded to the transducer chamber edge such that the cap, along with the transducer chamber floor and the transducer chamber walls, encloses the transducer chamber to form an enclosed air space between the ultrasonic transducer and the cap. ## Claims ### Claim 1 An apparatus, comprising: a base comprising a transducer chamber, wherein the transducer chamber comprises a transducer chamber floor, a transducer chamber edge, and transducer chamber walls extending from the transducer chamber floor to the transducer chamber edge; an ultrasonic transducer attached to the transducer chamber floor; and a cap welded to the transducer chamber edge and that, along with the transducer chamber floor and the transducer chamber walls, encloses the transducer chamber to form an enclosed air space between the ultrasonic transducer and the cap. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the base further comprises: a flange portion, and a mounting hole in the flange portion. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the base further comprises: a wiring channel in communication with the transducer chamber, wherein the wiring channel comprises a wiring channel floor, a wiring channel edge, and wiring channel walls extending from the wiring channel floor to the wiring channel edge; and wherein the cap is welded to the wiring channel edge. ### Claim 4 (depends on 3) The apparatus of claim 3 further comprising wires attached to the ultrasonic transducer and extending from the ultrasonic transducer, through the transducer chamber, through the wiring channel, and through the wiring channel floor. ### Claim 5 (depends on 4) The apparatus of claim 4, wherein the wires are soldered to the ultrasonic transducer. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein the ultrasonic transducer is a piezoelectric transducer. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein the cap is made of plastic. ### Claim 8 (depends on 7) The apparatus of claim 7, wherein the cap is made of polyphenylene sulphide. ### Claim 9 (depends on 1) The apparatus of claim 1 further comprising a tube attached to the base such that an ultrasonic signal generated by the ultrasonic transducer is directed into the tube. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein the base is attached to an inside surface of a fuel tank on an aircraft such that the tube extends from the base into the fuel tank. ### Claim 11 A method of enhancing reliability of an ultrasonic fluid measurement probe, comprising: generating an ultrasonic signal by an ultrasonic transducer in a transducer chamber in a base of the ultrasonic fluid measurement probe such that the ultrasonic signal is directed into a tube attached to the base of the ultrasonic fluid measurement probe, wherein the transducer chamber comprises a transducer chamber floor, transducer chamber walls, and a cap welded to an edge of the transducer chamber walls such that the cap, along with the transducer chamber floor and the transducer chamber walls, encloses the transducer chamber to form an enclosed air space; and detecting a reflection of the ultrasonic signal by the ultrasonic transducer. ### Claim 12 (depends on 11) The method of claim 11 further comprising processing the detected reflection of the ultrasonic signal to determine a level of fluid in a container. ### Claim 13 (depends on 11) The method of claim 11 wherein processing the detected reflection of the ultrasonic signal to determine the level of fluid in a container comprises processing the detected reflection of the ultrasonic signal to determine a level of fuel in a fuel tank. ### Claim 14 A method of enhancing reliability of an ultrasonic fluid measurement probe, comprising: attaching an ultrasonic transducer to a transducer chamber floor of a transducer chamber in a base, wherein the transducer chamber comprises the transducer chamber floor, a transducer chamber edge, and transducer chamber walls extending from the transducer chamber floor to the transducer chamber edge; and welding a cap to the transducer chamber edge such that the cap, along with the transducer chamber floor and the transducer chamber walls, encloses the transducer chamber to form an enclosed air space between the ultrasonic transducer and the cap. ### Claim 15 (depends on 14) The method of claim 14, wherein the base further comprises a wiring channel in communication with the transducer chamber, wherein the wiring channel comprises a wiring channel floor, a wiring channel edge, and wiring channel walls extending from the wiring channel floor to the wiring channel edge, and further comprising: welding the cap to the wiring channel edge. ### Claim 16 (depends on 15) The method of claim 15 further comprising: attaching wires to the ultrasonic transducer; and extending the wires from the ultrasonic transducer, through the transducer chamber, through the wiring channel, and through the wiring channel floor. ### Claim 17 (depends on 14) The method of claim 14, wherein the cap is made of plastic. ### Claim 18 (depends on 17) The method of claim 17, wherein the cap is made of polyphenylene sulphide. ### Claim 19 (depends on 17) The method of claim 17, wherein welding the cap to the transducer chamber edge comprises ultrasonically welding the cap to the transducer chamber edge. ### Claim 20 (depends on 14) The method of claim 14 further comprising attaching a tube to the base such that an ultrasonic signal generated by the ultrasonic transducer is directed into the tube.