US3849000A
Expired / Lapsed
US
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Digital display optical pyrometer
Assignee: INST ELETTROTECNICO NAZIONALE
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Filing: 1973-05-17
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Granted: 1974-11-19
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Expires: 1993-05-17
Abstract
Abstract WHERE A, B and C are constants. The first part of this expression is derived from the time interval taken for a capacitive storage circuit to discharge between voltage C V1 and V2 and the second part from a fixed time interval, both time intervals being recorded as a number of clock pulses in counters and combined in a digital display. This invention provides a digital display pyrometer which derives from the voltages V1 and V2 provided by photoelectric sensor means at a given temperature Tx to be measured a temperature signal, by reproducing in pulse-counting and gating circuits the following relation, derived from Planck''s law:
Inventors
- 👤 P Soardo
- 👤 M Pasta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:38
CPC Classifications
G; G01; G01J; G01J5/00; G01J5/60; H; H03; H03M; H03M1/00; H03M1/12; H03M1/60
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
280 words
Digital display optical pyrometer apparatus comprising photometric means adapted to emit respectively a first and a second electrical signal, corresponding to respective linear functions of two radiant energy fluxes incident on said means, circuit means connected to said photometric means to process the signals emitted thereby and to supply a digital signal proportional to the radiation temperature associated with said energy fluxes and visual display means piloted by said digital signal and providing a digital measurement of the said temperature, wherein the improvement consists in: a. a storage circuit having a discharge time constant proportional to the reciprocal of a preselected constant A; b. a charging and comparator circuit adapted to apply to said storage circuit a voltage not less than the product of said first signal and a second preselected constant C, for a predetermined first time interval, and to allow successively the discharge of the storage circuit to the value of the second signal so as to cause a sequence of charge and discharge cycles of said storage circuit to take place; c. a source of electrical clock pulses; and d. a logic circuit including first counter means arranged to count a number of pulses emitted by the source of clock pulses, said number being proportional to the expression (1n(1/C) B)/A wherein B is a third preselected constant and to emit at the termination of said counting an output pulse which initiates the functioning of said charging and comparator circuit to allow discharge of the storage circuit, said logic circuit further including second counter means which enables the application to said visual display means of the pulses counted by said first counter means during a preselected time interval.
Claim 2
Dependent Claim
280 words
Digital display optical pyrometer apparatus comprising photometric means adapted to emit respectively a first and a second electrical signal, corresponding to respective linear functions of two radiant energy fluxes incident on said means, circuit means connected to said photometric means to process the signals emitted thereby and to supply a digital signal proportional to the radiation temperature associated with said energy fluxes and visual display means piloted by said digital signal and providing a digital measurement of the said temperature, wherein the improvement consists in: a. a storage circuit having a discharge time constant proportional to the reciprocal of a preselected constant A; b. a charging and comparator circuit adapted to apply to said storage circuit a voltage not less than the product of said first signal and a second preselected constant C, for a predetermined first time interval, and to allow successively the discharge of the storage circuit to the value of the second signal so as to cause a sequence of charge and discharge cycles of said storage circuit to take place; c. a source of electrical clock pulses; and d. a logic circuit including first counter means arranged to count a number of pulses emitted by the source of clock pulses, said number being proportional to the expression (1n(1/C) B)/A wherein B is a third preselected constant and to emit at the termination of said counting an output pulse which initiates the functioning of said charging and comparator circuit to allow discharge of the storage circuit, said logic circuit further including second counter means which enables the application to said visual display means of the pulses counted by said first counter means during a preselected time interval.
Claim 3
Dependent Claim
52 words
The apparatus defined in claim 1, wherein said charging and comparator circuit includes a first comparator which records the instant in which the signal in the storage circuit becomes equal to the second signal to control resumption of charging of the storage circuit and the start of counting by said counter means.
Claim 4
Dependent Claim
79 words
The apparatus defined in claim 2, wherein the charging and comparator circuit includes a further comparator which records the instant in which the signal in the storage circuit becomes equal to the product of the first signal and the constant C, and thereupon supplies to the logic circuit a signal marking the instant of starting of the time during which the signal in the storage circuit is comprised between the value of said first and of said second signal.
Claim 5
Dependent Claim
14 words
The apparatus defined in claim 1, wherein the storage circuit is a resistance-capacitance circuit.
Claim 6
Dependent Claim
32 words
The apparatus defined in claim 1, wherein the constant A is proportional to the difference between the reciprocals of the wavelengths of the respective signals to which the photometric means are responsive.
Claim 7
Dependent Claim
31 words
The apparatus defined in claim 1, wherein the constant B is proportional to five times the natural logarithm of the ratio of two wavelengths to which the photometric means are responsive.
Claim 8
Dependent Claim
257 words
Digital display optical pyrometer apparatus comprising photometric means adapted to emit respectively a first and a second electrical signal corresponding to respective linear functions of two radiant energy fluxes incident on said photometric means, circuit means, connected to said photometric means to process the signals emitted thereby and to supply a digital signal proportional to the radiation temperature associated with said energy fluxes, and visual display means piloted by said digital signal and providing a digital measurement of the said temperature, wherein the improvement consists in: a. a storage circuit having a discharge time constant proportional to the reciprocal of a preselected constant A; b. a charging and comparator circuit adapted to apply to said storage circuit a voltage not less than the product of said first signal and a second preselected constant C, and to allow successively the discharge of the storage circuit to the value of the second signal, so as to cause a sequence of charge and discharge signals of said storage circuit to take place; c. a source of electrical clock pulses; and d. a logic circuit controlled by said source of clock pulses to enable application of the output pulses of said charging and comparator circuit to the visual display means during a number of clock pulses proportional to a preselected time reduced by a time n Delta t, where n is the number of discharges corresponding to one measurement and Delta t is an interval of time proportional to the factor (1n(1/C) - B)/A wherein B is a third preselected constant.
Claim 9
Dependent Claim
257 words
Digital display optical pyrometer apparatus comprising photometric means adapted to emit respectively a first and a second electrical signal corresponding to respective linear functions of two radiant energy fluxes incident on said photometric means, circuit means, connected to said photometric means to process the signals emitted thereby and to supply a digital signal proportional to the radiation temperature associated with said energy fluxes, and visual display means piloted by said digital signal and providing a digital measurement of the said temperature, wherein the improvement consists in: a. a storage circuit having a discharge time constant proportional to the reciprocal of a preselected constant A; b. a charging and comparator circuit adapted to apply to said storage circuit a voltage not less than the product of said first signal and a second preselected constant C, and to allow successively the discharge of the storage circuit to the value of the second signal, so as to cause a sequence of charge and discharge signals of said storage circuit to take place; c. a source of electrical clock pulses; and d. a logic circuit controlled by said source of clock pulses to enable application of the output pulses of said charging and comparator circuit to the visual display means during a number of clock pulses proportional to a preselected time reduced by a time n Delta t, where n is the number of discharges corresponding to one measurement and Delta t is an interval of time proportional to the factor (1n(1/C) - B)/A wherein B is a third preselected constant.
Claim 10
Dependent Claim
39 words
The apparatus defined in claim 7, wherein the logic circuit comprises counter means effective in each charge and discharge cycle of the storage circuit to advance the counted quantity by an amount corresponding to said factor, (1n(1/C) - B)/A.
References Cited (Backward Citations)
US3654809A
Cited
US3664744A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-18 | 1978-05-20 | 1978-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-18 | 1982-05-20 | 1982-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-18 | 1986-05-20 | 1986-11-19 | $7700.00 | Window Closed / Lapsed |