US3917407A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spectrophotometer with automatically fine tuned monochromator
Assignee: Pye Electronic Products Ltd
•
Filing: 1973-11-08
•
Granted: 1975-11-04
•
Expires: 1993-11-08
Abstract
Abstract Apparatus for automatically fine tuning a monochromator wherein an electrical oscillator drives an electromechanical transducer which varies the monochromator wave length and a detector responsive to the radiation beam from the monochromator controls a D.C. amplifier which servo controls the bias to the transducer.
Inventors
- 👤 Ronald Alfred Newstead
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:03
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/31; G01N21/3103; G01J; G01J3/00; G01J3/12
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
151 words
An atomic spectrophotometer including a monochromator, a detector responsive to the radiation beam coming from an exit slit of the monochromator to generate an electric output, and an arrangement capable of automatically fine tuning the monochromator wavelength when a selected spectral line has been positioned at least partly within said exit slit, said arrangement including an electromechanical transducer for adjusting the monochromator wavelength, a d.c. amplifier for biasing the transducer, an electrical oscillator for cyclically driving the transducer at a predetermined frequency to produce a signal component at said frequency in the output of the detector, and means responsive to said signal component for changing the input level of the d.c. amplifier in the direction which tends to reduce the amplitude of the signal component at said frequency, thereby adjusting the bias on the transducer to a value at which the selected spectral line is centered on the monochromator exit slit.
Claim 2
Dependent Claim
151 words
An atomic spectrophotometer including a monochromator, a detector responsive to the radiation beam coming from an exit slit of the monochromator to generate an electric output, and an arrangement capable of automatically fine tuning the monochromator wavelength when a selected spectral line has been positioned at least partly within said exit slit, said arrangement including an electromechanical transducer for adjusting the monochromator wavelength, a d.c. amplifier for biasing the transducer, an electrical oscillator for cyclically driving the transducer at a predetermined frequency to produce a signal component at said frequency in the output of the detector, and means responsive to said signal component for changing the input level of the d.c. amplifier in the direction which tends to reduce the amplitude of the signal component at said frequency, thereby adjusting the bias on the transducer to a value at which the selected spectral line is centered on the monochromator exit slit.
Claim 3
Dependent Claim
53 words
A spectrophotometer as claimed in claim 1, in which the monochromator includes a dispersive element with means for rotating said element to position the selected spectral line at least partly within said exit slit, and in which deflecting means within the monochromator are adjustable by said electromechanical transducer to fine tune the monochromator.
Claim 4
Dependent Claim
43 words
A spectrophotometer as claimed in claim 2, in which said deflecting means is a mirror on a rotatable support, and in which said electromechanical transducer is a piezoelectric bender element having one end fixed and the other end freely contacting said rotatable support.
Claim 5
Dependent Claim
60 words
A spectrophotometer as claimed in any one of claim 1 in which said input level changing means includes a phase sensitive detector circuit to which is fed the signal component at said predetermined frequency and a reference signal from the oscillator, and an integrating circuit connected between the output of the detector circuit and the input of the d.c. amplifier.
Claim 6
Dependent Claim
78 words
A spectrophotometer as claimed in claim 4, in which the intensity of the radiation beam entering the monochromator is modulated at another predetermined frequency, in which frequency sorting means passes the signal component at said predetermined frequency to the phase sensitive detector circuit of said input level changing means and passes a signal at said other predetermined frequency to a respective other phase sensitive detector circuit whose output is fed via a respective integrating circuit to measure means.
Claim 7
Dependent Claim
77 words
A spectrophotometer as claimed in claim 1 in which a switching means is provided which operates between a first position in which both the oscillator and the d.c. amplifier are connected to the transducer and a second position in which the oscillator is disconnected from the transducer and regenerating means are connected between the d.c. amplifier and the transducer to maintain a bias on the transducer which keeps the selected spectral line centred on the monochromator slit.
Claim 8
Dependent Claim
57 words
A spectrophotometer as claimed in claim 6, in which a sample delivery mechanism is provided to automatically present a series of samples for analysis in relation to the same spectral line, and in which said mechanism is adapted to operate said switching means between said first and second positions to automatically retune the monochromator for each analysis.
Claim 9
Dependent Claim
55 words
A spectrophotometer as claimed in claim 6, in which a servo-mechanism is provided to position a selected spectral line at least partly within the exit slit of the monochromator, and in which said servo mechanism is connected by timing means to said switching means whereby the monochromator is automatically tuned for a selected spectral line.
References Cited (Backward Citations)
US2837959A
Cited
US3064520A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-03 | 1979-05-05 | 1979-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-03 | 1983-05-05 | 1983-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-03 | 1987-05-05 | 1987-11-04 | $7700.00 | Window Closed / Lapsed |