Patent US3091957A successfully refreshed from Google Patents.
US3091957A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal conductivity bridge circuit
Assignee: AMERICAN INSTR CO Inc
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Filing: 1959-10-14
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Granted: 1963-06-04
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Expires: 1979-10-14
Abstract
No abstract record available.
Inventors
- 👤 William C Hampton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:02
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/14; G01N27/18; G01N27/185
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
184 words
IN A GAS CHROMATOGRAPHY APPARATUS, A THERMAL CONDUCTIVITY CELL, RESPECTIVE DETECTOR AND REFERENCE THERMISTORS IN SAID CELL, A CONSTANT VOLTAGE SOURCE OF DIRECT CURRENT, A PAIR OF INPUT TERMINALS, A FIRST CIRCUIT BRANCH CONNECTED BETWEEN SAID INPUT TERMINALS COMPRISING A FIRST ADJUSTABLE RESISTANCE MEMBER AND SAID DETECTOR THERMISTOR CONNECTED IN SERIES, A SECOND CIRCUIT BRANCH CONNECTED BETWEEN SAID INPUT TERMINALS COMPRISING A SECOND ADJUSTABLE RESISTANCE MEMBER AND SAID REFERENCE THERMISTOR CONNECTED IN SERIES, SAID FIRST AND SECOND ADJUSTABLE RESISTANCE MEMBERS HAVING DIFFERENT SETTINGS CORRESPONDING TO DIFFERENT TEMPERATURE RANGES, AN INDICATING CIRCUIT BRANCH, MEANS CONNECTING SAID INDICATING CIRCUIT BRANCH BETWEEN POINTS ON SAID FIRST AND SECOND CIRCUIT BRANCHES ELECTRICALLY LOCATED RESPECTIVELY BETWEEN THE FIRST ADJUSTABLE RESISTANCE MEMBER AND THE DETECTOR THERMISTOR AND BETWEEN THE SECOND ADJUSTABLE RESISTANCE MEMBER AND THE REFERENCE THERMISTOR, A THIRD ADJUSTABLE RESISTANCE MEMBER, MEANS CONNECTING SAID SOURCE TO SAID INPUT TERMINALS THROUGH SAID THIRD ADJUSTABLE MEMBER, WHEREBY TO DEFINE A BRIDGE CIRCUIT WHEREIN A SIGNAL CURRENT WILL BE DEVELOPED IN SAID INDICATING CIRCUIT BRANCH RESPONSIVE TO A RELATIVE CHANGE IN THERMAL CONDUCTIVITY ADJACENT SAID DETECTOR AND REFERENCE THERMISTORS, AND MEANS MECHANICALLY
Claim 2
Dependent Claim
184 words
IN A GAS CHROMATOGRAPHY APPARATUS, A THERMAL CONDUCTIVITY CELL, RESPECTIVE DETECTOR AND REFERENCE THERMISTORS IN SAID CELL, A CONSTANT VOLTAGE SOURCE OF DIRECT CURRENT, A PAIR OF INPUT TERMINALS, A FIRST CIRCUIT BRANCH CONNECTED BETWEEN SAID INPUT TERMINALS COMPRISING A FIRST ADJUSTABLE RESISTANCE MEMBER AND SAID DETECTOR THERMISTOR CONNECTED IN SERIES, A SECOND CIRCUIT BRANCH CONNECTED BETWEEN SAID INPUT TERMINALS COMPRISING A SECOND ADJUSTABLE RESISTANCE MEMBER AND SAID REFERENCE THERMISTOR CONNECTED IN SERIES, SAID FIRST AND SECOND ADJUSTABLE RESISTANCE MEMBERS HAVING DIFFERENT SETTINGS CORRESPONDING TO DIFFERENT TEMPERATURE RANGES, AN INDICATING CIRCUIT BRANCH, MEANS CONNECTING SAID INDICATING CIRCUIT BRANCH BETWEEN POINTS ON SAID FIRST AND SECOND CIRCUIT BRANCHES ELECTRICALLY LOCATED RESPECTIVELY BETWEEN THE FIRST ADJUSTABLE RESISTANCE MEMBER AND THE DETECTOR THERMISTOR AND BETWEEN THE SECOND ADJUSTABLE RESISTANCE MEMBER AND THE REFERENCE THERMISTOR, A THIRD ADJUSTABLE RESISTANCE MEMBER, MEANS CONNECTING SAID SOURCE TO SAID INPUT TERMINALS THROUGH SAID THIRD ADJUSTABLE MEMBER, WHEREBY TO DEFINE A BRIDGE CIRCUIT WHEREIN A SIGNAL CURRENT WILL BE DEVELOPED IN SAID INDICATING CIRCUIT BRANCH RESPONSIVE TO A RELATIVE CHANGE IN THERMAL CONDUCTIVITY ADJACENT SAID DETECTOR AND REFERENCE THERMISTORS, AND MEANS MECHANICALLY
References Cited (Backward Citations)
US2649715A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1966-06-03 | 1966-12-03 | 1967-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-06-03 | 1970-12-03 | 1971-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-06-03 | 1974-12-03 | 1975-06-04 | $7700.00 | Window Closed / Lapsed |