US3650631A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Arrangement and process for measuring the refractive index of liquids
Assignee: Bayer AG
•
Filing: 1970-04-30
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Granted: 1972-03-21
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Expires: 1990-04-30
Abstract
Abstract A two-beam arrangement for measuring the refractive index of liquids using the fact that the intensity of a measuring light beam reflected at an interface between a solid reference body and a sample liquid is governed by the refractive index of the sample liquid when the angle of incidence of the light beam striking the interface is smaller than the critical angle of total reflection, in which arrangement the measuring beam and comparison beam are reflected at the same point along an interface between a measuring liquid sample and a reference body, the angle of incidence of the measuring beam being smaller and the angle of incidence of the comparison beam being greater than the critical angle of total reflection.
Inventors
- 👤 Joachim Grassel
- 👤 Otto Petersen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:56
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/41; G01N21/43
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
133 words
Apparatus for measuring the refractive index of liquids comprising: a. a specimen holder for the liquid including a chamber for the liquid and a solid body for disposing the liquid in interfacial contact with a surface of the solid body, b. light providing means for directing a measuring beam onto said interface at an angle of incidence less than the critical angle of total reflection for reflection from said interface of part of said beam in an amount depending on the refractive index of the sample liquid, and for directing a comparison beam onto said interface at an angle of incidence greater than the critical angle of total reflection for total reflection of the comparison beam from said interface, c. comparing means for comparing the intensities of the reflected measuring and comparison beams.
Claim 2
Dependent Claim
133 words
Apparatus for measuring the refractive index of liquids comprising: a. a specimen holder for the liquid including a chamber for the liquid and a solid body for disposing the liquid in interfacial contact with a surface of the solid body, b. light providing means for directing a measuring beam onto said interface at an angle of incidence less than the critical angle of total reflection for reflection from said interface of part of said beam in an amount depending on the refractive index of the sample liquid, and for directing a comparison beam onto said interface at an angle of incidence greater than the critical angle of total reflection for total reflection of the comparison beam from said interface, c. comparing means for comparing the intensities of the reflected measuring and comparison beams.
Claim 3
Dependent Claim
22 words
Apparatus according to claim 1, said light providing means directing the comparison and measuring beams onto the same point of said interface.
Claim 4
Dependent Claim
59 words
Apparatus according to claim 2, said light providing means comprising a light source, a double diaphragm for production of the measuring beam and comparison beam from light issuing from the light source, and a rotatable diaphragm wheel interposed between said double diaphragm and the specimen holder for alternate passage of the measuring beam and comparison beam to said interface.
Claim 5
Dependent Claim
24 words
Apparatus according to claim 3, and a lens for focusing the measuring beam and the comparison beam on the same point of said interface.
Claim 6
Dependent Claim
31 words
Apparatus according to claim 4, said comparison means comprising a photocell for alternately converting the reflected measuring and comparison beams into electrical signals, and means for comparing the respective electrical signals.
Claim 7
Dependent Claim
31 words
Apparatus as claimed in claim 5, and a light-dimming device controlled by a differential signal generated from the measuring beam and comparison beam arranged in the path of the comparison beam.
Claim 8
Dependent Claim
21 words
Apparatus according to claim 5, and means for pivoting the specimen holder for varying the angle of incidence of said beams.
Claim 9
Dependent Claim
21 words
Apparatus according to claim 1, and means for pivoting the specimen holder for varying the angle of incidence of said beams.
Claim 10
Dependent Claim
34 words
Apparatus according to claim 7, the solid body of the specimen holder being a hemisphere disposed for entrance thereinto of the measuring and comparison beams along radial lines thereof, for reflection from the interface.
Claim 11
Dependent Claim
34 words
Apparatus according to claim 1, the solid body of the specimen holder being a hemisphere disposed for entrance thereinto of the measuring and comparison beams along radial lines thereof, fOr reflection from the interface.
Claim 12
Dependent Claim
154 words
Process of measuring refractive index of liquids which comprises a. disposing the liquid in a specimen holder comprising a chamber for the liquid and a solid body for disposing the liquid in interfacial contact with a surface of the solid body, b. directing a measuring and a comparison beam through the specimen holder onto the interface of the liquid and solid body of the specimen holder, with light providing means for directing the measuring beam onto said interface at an angle of incidence less than the critical angle of total reflection for reflection from said interface of part of said beam in an amount depending on the refractive index of the sample liquid, and for directing the comparison beam onto said interface at an angle of incidence greater than the critical angle of total reflection for total reflection of the comparison beam from said interface, c. comparing the intensities of the respective reflected beams.
Claim 13
Dependent Claim
154 words
Process of measuring refractive index of liquids which comprises a. disposing the liquid in a specimen holder comprising a chamber for the liquid and a solid body for disposing the liquid in interfacial contact with a surface of the solid body, b. directing a measuring and a comparison beam through the specimen holder onto the interface of the liquid and solid body of the specimen holder, with light providing means for directing the measuring beam onto said interface at an angle of incidence less than the critical angle of total reflection for reflection from said interface of part of said beam in an amount depending on the refractive index of the sample liquid, and for directing the comparison beam onto said interface at an angle of incidence greater than the critical angle of total reflection for total reflection of the comparison beam from said interface, c. comparing the intensities of the respective reflected beams.
Claim 14
Dependent Claim
19 words
Process according to claim 11, and directing said measuring and comparison beams onto the same point of the interface.
References Cited (Backward Citations)
US2445499A
Cited
US2885923A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-21 | 1975-09-20 | 1976-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-21 | 1979-09-20 | 1980-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-21 | 1983-09-20 | 1984-03-21 | $7700.00 | Window Closed / Lapsed |