US3666941A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Differential filter fluorimeter
Assignee: LAB DATA CONTROL Inc
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Filing: 1970-09-28
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Granted: 1972-05-30
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Expires: 1990-09-28
Abstract
Abstract There is disclosed a double beam differential fluorimeter requiring no light chopper and characterized by unusually small cell volume and high optical efficiency. The instrument comprises a bifurcated conical light tunnel having highly reflecting internal surfaces. A transparent tube passes through each side of the bifurcated light tunnel, one for containing a sample fluid, the other for containing a reference fluid. A light source directs ultraviolet radiation into the large end of the conical tunnel. A pair of photodetectors are positioned at the small end of the tunnel, together with an ultraviolet blocking filter. Each detector is responsive, respectively, to fluorescence from the sample and reference fluids. An electrical bridge circuit compares the intensities of the fluorescence derived from the sample and reference fluids.
Inventors
- 👤 Emmett S Watson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:41
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/62; G01N21/63; G01N21/64; G01N21/645; G01J; G01J1/00; G01J1/10; G01J1/16; G01J1/1626; G01N2201/00; G01N2201/08; G01N2201/0806
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
108 words
Apparatus for differential filter fluorimetry which comprises: a source of excitation radiation; a longitudinally bifurcated substantially conical light tunnel having highly reflective internal surfaces; means for placing a sample material within a first half of said light tunnel; means for placing a reference material within the second half of said light tunnel; means for directing said excitation radiation into a first end of said light tunnel to impinge upon said sample and reference materials with substantially equal intensities; and means at a second end of said light tunnel substantially solely responsive to fluorescence radiation from each of said first and second halves for indicating the relative intensities thereof.
Claim 2
Dependent Claim
108 words
Apparatus for differential filter fluorimetry which comprises: a source of excitation radiation; a longitudinally bifurcated substantially conical light tunnel having highly reflective internal surfaces; means for placing a sample material within a first half of said light tunnel; means for placing a reference material within the second half of said light tunnel; means for directing said excitation radiation into a first end of said light tunnel to impinge upon said sample and reference materials with substantially equal intensities; and means at a second end of said light tunnel substantially solely responsive to fluorescence radiation from each of said first and second halves for indicating the relative intensities thereof.
Claim 3
Dependent Claim
15 words
The apparatus of claim 1 wherein said first end is larger than said second end.
Claim 4
Dependent Claim
51 words
The apparatus of claim 1 wherein said responsive means comprises a power supply and a Wheatstone bridge energized by said power supply for producing an output signal indicative of said relative intensities, said Wheatstone bridge including first and second photosensitive elements responsive, respectively, to radiation from said first and second halves.
Claim 5
Dependent Claim
42 words
The apparatus of claim 3 wherein said power supply is of the feedback type and said responsive means includes a third photosensitive element responsive to the intensity of said excitation radiation source to supply a corresponding feedback signal to said power supply.
Claim 6
Dependent Claim
23 words
The apparatus of claim 1 wherein said source comprises: a lamp; and adjustable aperture defining means intermediate said lamp and said light tunnel.
Claim 7
Dependent Claim
27 words
The apparatus of claim 5 wherein said aperture defining means comprises: an opaque member defining a fixed aperture therein; and movable shutter means adjacent said fixed aperture.
Claim 8
Dependent Claim
48 words
The apparatus of claim 6 wherein said movable shutter means defines a supplemental aperture smaller than said fixed aperture and said shutter means is movable between a fixed position fully exposing said fixed aperture and a second position wherein said supplemental aperture is aligned with said fixed aperture.
Claim 9
Dependent Claim
120 words
Apparatus for differential filter fluorimetry which comprises: a source of excitation radiation; a longitudinally bifurcated light tunNel; means associated with said light tunnel for adjustably positioning supplemental fluorescent material in the path of said excitation radiation; means for placing a sample material within a first half of said light tunnel; means for placing a reference material within the second half of said light tunnel; means for directing said excitation radiation into a first end of said light tunnel to impinge upon said sample and reference materials with substantially equal intensities; and means at a second end of said light tunnel substantially solely responsive to fluorescence radiation from each of said first and second halves for indicating the relative intensities thereof.
Claim 10
Dependent Claim
120 words
Apparatus for differential filter fluorimetry which comprises: a source of excitation radiation; a longitudinally bifurcated light tunNel; means associated with said light tunnel for adjustably positioning supplemental fluorescent material in the path of said excitation radiation; means for placing a sample material within a first half of said light tunnel; means for placing a reference material within the second half of said light tunnel; means for directing said excitation radiation into a first end of said light tunnel to impinge upon said sample and reference materials with substantially equal intensities; and means at a second end of said light tunnel substantially solely responsive to fluorescence radiation from each of said first and second halves for indicating the relative intensities thereof.
Claim 11
Dependent Claim
34 words
The apparatus of claim 8, wherein said positioning means comprises first and second screw means positioned, respectively, in said first and second halves, each of said screw means supporting said supplemental fluorescent material thereon.
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) | 1975-05-30 | 1975-11-29 | 1976-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-30 | 1979-11-29 | 1980-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-30 | 1983-11-29 | 1984-05-30 | $7700.00 | Window Closed / Lapsed |