Patent FR1350652A successfully refreshed from Google Patents.
US4072046A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acoustic pycnometer
Assignee: Dow Chemical Co
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Filing: 1976-09-03
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Granted: 1978-02-07
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Expires: 1996-09-03
Abstract
Abstract An improved pycnometer in which the sample whose volume to be measured is put in a closed chamber to which an electro-mechanical transducer is coupled. The transducer is excited at a constant frequency. The change in impedance of the transducer is then read as a function of the volume of the sample.
Inventors
- 👤 Binneg Y. Lao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:14
CPC Classifications
G; G01; G01N; G01N29/00; G01N29/04; G01N29/11
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
117 words
Pycnometer apparatus comprising an enclosable chamber for receiving a sample whose volume is to be measured, an electro-acoustical transducer coupled to the interior of said chamber, electronic signal generator means for electrically energizing said transducer at a predetermined frequency having a wave length at least four times the longest dimension of said chamber, electrical bridge circuit means coupled between said means for electrically energizing and said electro-mechanical transducer, said bridge circuit including means for nulling the signal across said bridge circuit when said chamber is empty, and means for reading the signal across said bridge when a sample is disposed in said chamber, the magnitude of said signal being a function of the volume of the sample.
Claim 2
Dependent Claim
117 words
Pycnometer apparatus comprising an enclosable chamber for receiving a sample whose volume is to be measured, an electro-acoustical transducer coupled to the interior of said chamber, electronic signal generator means for electrically energizing said transducer at a predetermined frequency having a wave length at least four times the longest dimension of said chamber, electrical bridge circuit means coupled between said means for electrically energizing and said electro-mechanical transducer, said bridge circuit including means for nulling the signal across said bridge circuit when said chamber is empty, and means for reading the signal across said bridge when a sample is disposed in said chamber, the magnitude of said signal being a function of the volume of the sample.
Claim 3
Dependent Claim
17 words
Apparatus in accordance with claim 1, wherein said electro-mechanical transducer is a dynamic microphone or dynamic speaker.
Claim 4
Dependent Claim
20 words
Apparatus in accordance with claim 1, wherein said means for nulling said signal includes a variable inductance and variable resistance.
Claim 5
Dependent Claim
14 words
Apparatus in accordance with claim 1, wherein said chamber includes opening and closing means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-02-06 | 1981-08-08 | 1982-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-06 | 1985-08-08 | 1986-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-06 | 1989-08-08 | 1990-02-07 | $7700.00 | Window Closed / Lapsed |