US3677925A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for measuring ph
Assignee: Yokogawa Electric Corp
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Filing: 1970-07-22
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Granted: 1972-07-18
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Expires: 1990-07-22
Abstract
Abstract A GLASS ELECTRODE HAVING SUPPORT TUBE MEANS, AN INNER ELECTRODE DISPOSED THEREIN, A CAP FORMED OF AN INSULATING MATERIAL AND FIXED ON THE TOP OF THE SUPPORT TUBE MEANS, A GLASS ELECTRODE TERMINAL PROVIDED ON THE CAP AND CONNECTED WITH THE INNER ELECTRODE, A GUARD RING FIXED ON THE PERIPHERY OF THE CAP AND A GUARD RING TERMINAL, IN WHICH A NEGATIVE FEEDBACK VOLTAGE FROM A NEGATIVE FEEDBACK AMPLIFIER IS IMPRESSED TO THE GUARD TERMINAL, THE NEGATIVE FEEDBACK AMPLIFIER AMPLIFYING A SIGNAL DERIVED AT THE GLASS ELECTRODE TERMINAL. D R A W I N G
Inventors
- 👤 Tokutaro Tamate
- 👤 Hisayuki Ikeda
- 👤 Eiichi Yagi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:27
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/28; G01N27/30; G01N27/36
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) | 1975-07-18 | 1976-01-17 | 1976-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-18 | 1980-01-17 | 1980-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-18 | 1984-01-17 | 1984-07-18 | $7700.00 | Window Closed / Lapsed |