US3792345A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Checking and calibration of apparatus incorporating a resonant circuit
Assignee: Newport Instruments Ltd
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Filing: 1972-04-14
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Granted: 1974-02-12
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Expires: 1992-04-14
Abstract
Abstract In the use of spectrometric apparatus incorporating a resonant circuit an artificial signal is generated for checking, calibration or measurement purposes. The artificial signal is generated by periodically switching a resistance into and out of circuit with the resonant circuit, preferably also biasing out the normal resonance signals. It is particularly applicable to the monitoring of on-line flow systems.
Inventors
- 👤 F Hawkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:54
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/46
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
156 words
A method of calibrating or checking spectrometric apparatus or using such apparatus to measure the condition or properties of a material, the spectrometric apparatus incorporating oscillator means having a resonance circuit comprising a sensing coil arranged to surround a sample of a material under test and through which a high frequency oscillatory magnetic field can be applied to the sample, the method comprising positioning the sample within a unidirectional magnetic field, subjecting the sample to a high frequency oscillatory magnetic field at rightangles to the direction of the unidirectional field, connecting a resistance and switch means in circuit with the oscillator resonance circuit, controlling said switch means to switch said resistance periodically into and out of circuit with the resonance circuit to generate a train of artificial pulses, and during the generation of said artificial pulses inhibiting the generation of resonance pulses from the sample by biassing the magnetic field in which the sample is located.
Claim 2
Independent Claim
156 words
A method of calibrating or checking spectrometric apparatus or using such apparatus to measure the condition or properties of a material, the spectrometric apparatus incorporating oscillator means having a resonance circuit comprising a sensing coil arranged to surround a sample of a material under test and through which a high frequency oscillatory magnetic field can be applied to the sample, the method comprising positioning the sample within a unidirectional magnetic field, subjecting the sample to a high frequency oscillatory magnetic field at rightangles to the direction of the unidirectional field, connecting a resistance and switch means in circuit with the oscillator resonance circuit, controlling said switch means to switch said resistance periodically into and out of circuit with the resonance circuit to generate a train of artificial pulses, and during the generation of said artificial pulses inhibiting the generation of resonance pulses from the sample by biassing the magnetic field in which the sample is located.
Claim 3
Dependent Claim
47 words
A method as claimed in claim 1, in which said resistance is connected into or out of circuit with the resonance circuit at such times as to cause the artificial pulses to be generated substantially at the normal times of occurrence of resonance pulses from the sample.
Claim 4
Dependent Claim
51 words
A method as claimed in claim 1, in which the switch means is controlled from a scan waveform generator which also modulates the field strength of the unidirectional magnetic field in which the sample is located to cause the resultant magnetic field to pass through the resonance condition for the sample.
Claim 5
Dependent Claim
41 words
A method as claimed in claim 3, in which the switch means is actuated to connect the resistance into or out of circuit with the resonance circuit for a period of between 4 and 5 milliseconds in each scan waveform cycle.
Claim 6
Independent Claim
182 words
A method of using spectrometric apparatus to measure the condition or properties of a material, the spectrometric apparatus incorporating oscillator means having a resonance circuit comprising a sensing coil arranged to surround a sample of a material under test and through which a high frequency oscillatory magnetic field can be applied to the sample, the method comprising positioning the sample within a unidirectional magnetic field, subjecting the sample to a high frequency oscillatory magnetic field at right-angles to the direction of the unidirectional field, connecting a resistance and switch means in circuit with the oscillator resonance circuit, controlling said switch means to switch said resistance periodically into and out of circuit with the resonance circuit to generate artificial pulse of opposite polarity to the resonance pulses from the sample, feeding a predetermined number of resonance pulses from the sample to integrating means, feeding a train of said artificial pulses to said integrating means to discharge the integrating means to zero, and counting the number of artificial pulses in said train thereby to give a measurement of the resonance signal from the sample.
Claim 7
Independent Claim
182 words
A method of using spectrometric apparatus to measure the condition or properties of a material, the spectrometric apparatus incorporating oscillator means having a resonance circuit comprising a sensing coil arranged to surround a sample of a material under test and through which a high frequency oscillatory magnetic field can be applied to the sample, the method comprising positioning the sample within a unidirectional magnetic field, subjecting the sample to a high frequency oscillatory magnetic field at right-angles to the direction of the unidirectional field, connecting a resistance and switch means in circuit with the oscillator resonance circuit, controlling said switch means to switch said resistance periodically into and out of circuit with the resonance circuit to generate artificial pulse of opposite polarity to the resonance pulses from the sample, feeding a predetermined number of resonance pulses from the sample to integrating means, feeding a train of said artificial pulses to said integrating means to discharge the integrating means to zero, and counting the number of artificial pulses in said train thereby to give a measurement of the resonance signal from the sample.
Claim 8
Dependent Claim
134 words
Spectrometric apparatus comprising magnetic means providing a unidirectional magnetic field, oscillator means having a resonance circuit comprising a sensing coil arranged to surround a sample of a material under test and through which a high frequency oscillatory magnetic field can be applied to the sample perpendicular to said unidirectional magnetic field, a resistance and switch means connected in circuit witH the oscillator resonance circuit, drive circuit means connected to said switch means and arranged to trigger said switch means to switch said resistance periodically into and out of circuit with the resonance circuit thereby to generate a train of artificial pulses, and biassing means operative only during the generation of said artificial pulses to bias the magnetic field in which the sample is located and inhibit the generation of resonance pulses from the sample.
Claim 9
Dependent Claim
134 words
Spectrometric apparatus comprising magnetic means providing a unidirectional magnetic field, oscillator means having a resonance circuit comprising a sensing coil arranged to surround a sample of a material under test and through which a high frequency oscillatory magnetic field can be applied to the sample perpendicular to said unidirectional magnetic field, a resistance and switch means connected in circuit witH the oscillator resonance circuit, drive circuit means connected to said switch means and arranged to trigger said switch means to switch said resistance periodically into and out of circuit with the resonance circuit thereby to generate a train of artificial pulses, and biassing means operative only during the generation of said artificial pulses to bias the magnetic field in which the sample is located and inhibit the generation of resonance pulses from the sample.
Claim 10
Dependent Claim
54 words
Apparatus as claimed in claim 6, which includes a scan waveform generator which is arranged to modulate the field strength of said unidirectional magnetic field to cause the resultant magnetic field to pass through the resonance condition for the sample and which is also arranged to provide actuating signals for said drive circuit means.
Claim 11
Dependent Claim
104 words
Apparatus as claimed in claim 7, in which said drive circuit means comprises a differential comparator having one input connected to receive the output of the scan waveform generator and the other input connected to receive bias voltages, and a transistor switch connected between the output of the comparator and said switch means, the drive circuit means and switch means being connected in such manner that with no input from the scan waveform generator said switch means is turned off and with an input from the scan waveform generator said switch means is turned on for a proportion only of each scan waveform cycle.
Claim 12
Dependent Claim
22 words
Apparatus as claimed in claim 8, which includes temperature compensation means comprising a thermistor connected into the input circuit of the comparator.
Claim 13
Dependent Claim
144 words
Spectrometric apparatus comprising magnetic means providing a unidirectional magnetic field, oscillator means having a resonance circuit comprising a sensing coil arranged to surround a sample of material under test and through which a high frequency oscillatory magnetic field can be applied to the sample perpendicular to said unidirectional magnetic field, a resistance and switch means connected in circuit with the oscillator resonance circuit, drive circuit means connected to said switch means and arranged to trigger said switch means to switch said resistance periodically into and out of circuit with the resonance circuit thereby to generate artificial pulses of opposite polarity to the resonance pulses from the sample, integrator means connected to be charged by said resonance pulses and to be discharged by said artificial pulses, and counter means arranged to provide a measure of the number of artificial pulses fed to said integrator means.
Claim 14
Dependent Claim
144 words
Spectrometric apparatus comprising magnetic means providing a unidirectional magnetic field, oscillator means having a resonance circuit comprising a sensing coil arranged to surround a sample of material under test and through which a high frequency oscillatory magnetic field can be applied to the sample perpendicular to said unidirectional magnetic field, a resistance and switch means connected in circuit with the oscillator resonance circuit, drive circuit means connected to said switch means and arranged to trigger said switch means to switch said resistance periodically into and out of circuit with the resonance circuit thereby to generate artificial pulses of opposite polarity to the resonance pulses from the sample, integrator means connected to be charged by said resonance pulses and to be discharged by said artificial pulses, and counter means arranged to provide a measure of the number of artificial pulses fed to said integrator means.
Claim 15
Dependent Claim
15 words
Apparatus as claimed in claim 10, in which the switch means comprises a field-effect transistor.
References Cited (Backward Citations)
US3531715A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |