US4361802A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gas analyzer
Assignee: SENSORMEDICS BV A NETHERLANDS CORP
•
Filing: 1980-09-09
•
Granted: 1982-11-30
•
Expires: 2000-09-09
Abstract
Abstract A gas analyzer comprising a Wheatstone bridge, consisting of resistance wires, which are provided in two mutually separated channels of a measuring block. The resistance wires of opposite legs of the bridge are contained in the same channel, wherein a reference gas may be conducted through a first one of said channels and a gas to be analyzed may be conducted through a second one of said channels. The current through the bridge is controlled during a measurement in such a manner that the resistance of the resistance wires in the second channel remains substantially constant.
Inventors
- 👤 Johannes G. T. Luijpers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:14
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/0004; G01N33/0009; G01N33/0027; G01N33/0031; G01N27/00; G01N27/02; G01N27/04; G01N27/14; G01N27/18
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
167 words
A gas analyser comprising a measuring block having two mutually separated channels, a first of said channels being adapted for conducting a reference gas therethrough and a second of said channels being adapted for conducting a gas to be analysed therethrough, a first Wheatstone bridge consisting of resistance wires provided in said two channels of the measuring block, the resistance wires of opposite legs of the first bridge being connected in the same channel, a second Wheatstone bridge, wherein the first Wheatstone bridge forms one leg of said second Wheatstone bridge, and means for controlling feeding current for said second Wheatstone bridge to maintain said second Wheatstone bridge balanced, wherein the leg of said second Wheatstone bridge connected in series with the first Wheatstone bridge consists of a resistance, the physical properties of which correspond to those of the resistance wires of said first Wheatstone bridge, the current per unity of cross-section for said resistance being smaller than for the total resistance of said first Wheatstone bridge.
Claim 2
Dependent Claim
167 words
A gas analyser comprising a measuring block having two mutually separated channels, a first of said channels being adapted for conducting a reference gas therethrough and a second of said channels being adapted for conducting a gas to be analysed therethrough, a first Wheatstone bridge consisting of resistance wires provided in said two channels of the measuring block, the resistance wires of opposite legs of the first bridge being connected in the same channel, a second Wheatstone bridge, wherein the first Wheatstone bridge forms one leg of said second Wheatstone bridge, and means for controlling feeding current for said second Wheatstone bridge to maintain said second Wheatstone bridge balanced, wherein the leg of said second Wheatstone bridge connected in series with the first Wheatstone bridge consists of a resistance, the physical properties of which correspond to those of the resistance wires of said first Wheatstone bridge, the current per unity of cross-section for said resistance being smaller than for the total resistance of said first Wheatstone bridge.
Claim 3
Dependent Claim
53 words
A gas analyser according to claim 1, wherein said means for controlling include a differential amplifier having two inputs connected to the output terminals of the second Wheatstone bridge and controlling means for the feeding current of said second Wheatstone bridge, said controlling means being connected to the output of said differential amplifier.
Claim 4
Dependent Claim
31 words
A gas analyser according to claim 2, wherein one of the output terminals of the second Wheatstone bridge consists of a tapping point of a potentiometer connected in said second bridge.
References Cited (Backward Citations)
US2565230A
Cited
NL6710467A
Cited
GB1372695A
Cited
US3868846A
Cited
US3913379A
Cited
US4123934A
Cited
US4057755A
Cited
FR2374639A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-11-29 | 1986-05-31 | 1986-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-29 | 1990-05-31 | 1990-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-29 | 1994-05-31 | 1994-11-30 | $7700.00 | Window Closed / Lapsed |