US4229105A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sensitive measuring cell for a differential refractometer of the interference type
Assignee: Individual
•
Filing: 1979-04-12
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Granted: 1980-10-21
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Expires: 1999-04-12
Abstract
Abstract A highly sensitive measuring cell for a differential refractometer of the interference type for chemical analyzers comprises two channels in a measuring body, one of said channels conveying a medium whose refractive index is to be measured and the other channel conveying a reference medium of known refractive index. The respective path lengths of the measuring channel and the reference channel are mechanically adjustable to exactly the same lengths in order that a maximum common mode rejection ratio (hereafter "CMRR") value may be achieved.
Inventors
- 👤 Sten Silverbage
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:34
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/41; G01N21/45
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
93 words
A highly sensitive measuring cell for an interference type of differential refractometer, said measuring cell comprising: (a) a measuring body provided with two channels, (b) one of said channels being a measuring channel for a medium whose refractive index is to be measured, and (c) the other measuring channel being a reference channel for a reference medium of a known refractive index, and (d) means for mechanically adjusting the respective path lengths of said measuring channel and of said reference channel to exactly the same geometrical length for achieving a maximum CMRR value.
Claim 2
Dependent Claim
93 words
A highly sensitive measuring cell for an interference type of differential refractometer, said measuring cell comprising: (a) a measuring body provided with two channels, (b) one of said channels being a measuring channel for a medium whose refractive index is to be measured, and (c) the other measuring channel being a reference channel for a reference medium of a known refractive index, and (d) means for mechanically adjusting the respective path lengths of said measuring channel and of said reference channel to exactly the same geometrical length for achieving a maximum CMRR value.
Claim 3
Dependent Claim
66 words
A measuring cell in accordance with claim 1, wherein said adjustment is carried out by the geometry of the measuring body being changed in an interferometer in which the measuring body is disposed, with a medium introduced simultaneously into the two channels of the measuring body and having a different refractive index from that of the measuring medium, thus leaving the adjustment of the interferometer unaffected.
Claim 4
Dependent Claim
107 words
A measuring cell in accordance with claim 1, wherein said measuring body is formed by a metal block having a cylindrical cavity, said cylindrical cavity being provided with a metal bobbin, said metal bobbin being penetrated by channels and being surrounded by coil loops of such lengths that the best temperature compensation is achieved and through which the measuring medium and the reference medium, respectively, flow, said coil loops each having an inlet and an outlet, said outlet being connected to one end of each of said channels, with the other ends of said channels comprising outlets for the measuring medium and for the reference medium, respectively.
Claim 5
Dependent Claim
34 words
A measuring cell in accordance with claim 3, wherein said coil loops for the measuring medium and for the reference medium, respectively, are molded into a thermally conductive substance, such as a tin mass.
Claim 6
Dependent Claim
75 words
A measuring cell in accordance with claim 4, wherein the measuring body of said cell is disposed in an environment having an accurately controlled temperature and pressure, said measuring channel being adapted to convey a measuring medium having an accurately controlled temperature, said reference channel being adapted to convey a reference medium having an accurately controlled temperature, and both said measuring channel and said reference channel being adapted to transmit light of a predetermined wavelength.
Claim 7
Dependent Claim
65 words
A measuring cell in accordance with claim 5, said cell comprising blocks closely engaging insulating material which surrounds the measuring body and a thermal capacitor having high thermal capacity, said thermal capacitor also engaging the insulation around said measuring body for imparting a substantially even temeperature thereto, said temperature essentially being the same as the temperature of the measuring medium and the reference medium, respectively.
Claim 8
Dependent Claim
44 words
A measuring cell in accordance with claim 6, wherein the thermal capacity of said thermal capacitor is utilized for equalizing the temperatures of the measuring medium and the reference medium in consequence of said mediums being in good thermal contact with said thermal capacitor.
Claim 9
Dependent Claim
55 words
A measuring cell in accordance with claim 6, wherein said blocks are adapted to convey a medium having a thermostatically controlled temperature, with a thermostatically controlled medium being utilized for thermostatic precontrol of said measuring and reference media by means of good thermal contact between said thermostatically controlled medium and said measuring and reference media.
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) | 1983-10-21 | 1984-04-21 | 1984-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-21 | 1988-04-21 | 1988-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-21 | 1992-04-21 | 1992-10-21 | $7700.00 | Window Closed / Lapsed |