US3561253A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method of measurement of particulate mass
Assignee: THERMO SYSTEMS Inc
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Filing: 1969-03-26
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Granted: 1971-02-09
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Expires: 1989-03-26
Abstract
Abstract A PARTICLE MEASUREMENT APPARATUS HAVING AN OSCILLATOR CIRCUIT WITH A QUARTZ CRYSTAL CARRYING ELECTRODE FILMS TO DETECT PARTICLE MASS FORCE COLLECTED ON A SURFACE OF A FILM BY READING THE CHANGE IN THE RESONANT FREQUENCY OF THE QUARTZ CRYSTAL. THE OSCILLATOR CIRCUIT IS COMBINED WITH A DEVICE FOR FORCE-COLLECTING PARTICKLES ON THE ELECTRICALLY- DRIVEN FILM. THE ELECTRICAL SIGNAL OF THE OSCILLATOR CIRCUIT IS MONITORED BY A FREQUENCY-COUNTING DEVICE.
Inventors
- 👤 Frank D Dorman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:03
CPC Classifications
G; G01; G01N; G01N29/00; G01N29/02; G01N29/036; G01N2291/00; G01N2291/02; G01N2291/025; G01N2291/0256
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-08 | 1974-08-10 | 1975-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-08 | 1978-08-10 | 1979-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-08 | 1982-08-10 | 1983-02-09 | $7700.00 | Window Closed / Lapsed |