US4099413A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal noise thermometer
Assignee: Yokogawa Electric Corp
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Filing: 1977-06-13
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Granted: 1978-07-11
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Expires: 1997-06-13
Abstract
Abstract A thermal noise thermometer operating on the principle that the temperature of a resistor is related to the magnitude of the thermal noise signal produced in the resistor. The thermoseter comprises a temperature-sensing resistor, a shot noise source, means for selectively applying shot noise signals from the shot noise source to the resistor, a DC amplifier for amplifying the DC signal produced in the resistor, an AC amplifier for amplifying the AC signal produced in the resistor, and means for calculating the temperature to be measured from the output signal of the AC amplifier produced when the shot noise signal is applied to the resistor, the output signal of the AC amplifier produced when no shot noise signal is applied to the resistor, and the output signal of the DC amplifier.
Inventors
- 👤 Akira Ohte
- 👤 Makoto Imamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:44
CPC Classifications
G; G01; G01K; G01K7/00; G01K7/30
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
92 words
A thermal noise thermometer based on the principle that the magnitude of thermal noise signal produced in the resistor is a function of the temperature of the resistor, comprising: means to develop a shot noise signal; switch means to interruptedly apply said shot noise signal to said resistor; voltage-responsive means coupled to said resistor for producing output signals responsive to the voltage thereof in the different conditions of said switch means; and means coupled to the output of said voltage-responsive means for producing a measurement signal representing the temperature of said resistor.
Claim 2
Dependent Claim
92 words
A thermal noise thermometer based on the principle that the magnitude of thermal noise signal produced in the resistor is a function of the temperature of the resistor, comprising: means to develop a shot noise signal; switch means to interruptedly apply said shot noise signal to said resistor; voltage-responsive means coupled to said resistor for producing output signals responsive to the voltage thereof in the different conditions of said switch means; and means coupled to the output of said voltage-responsive means for producing a measurement signal representing the temperature of said resistor.
Claim 3
Dependent Claim
33 words
A thermometer as claimed in claim 1, wherein said voltage-responsive means includes means to develop a DC output signal derived from the DC component of the shot noise signal applied to the resistor.
Claim 4
Dependent Claim
69 words
A thermometer as claimed in claim 2, wherein said voltage-responsive means includes: means to produce a first-signal corresponding to the resistor thermal noise signal, a second signal corresponding to the combination of the thermal noise signal and the shot noise signal applied to the resistor; and means to cause said first and second signals to bear a constant relationship, whereby said DC signal provides a measure of the temperature.
Claim 5
Dependent Claim
62 words
A thermal noise thermometer as claimed in claim 1, including: means for shorting the resistor; and means for controlling the shot noise signal source to provide that the shot noise signal is equal to the thermal noise current flowing through the resistor when it is shorted, whereby the temperature of the resistor is indicated by the DC voltage produced in the resistor.
Claim 6
Dependent Claim
53 words
A thermal noise thermometer as claimed in claim 1, wherein the effective value of the shot noise applied to the resistor is expressed by In (rms) = 2q·Io·B where q is the charge of an electron, Io is the magnitude of the DC current, and B is the frequency bandwidth of the noise.
Claim 7
Dependent Claim
55 words
A thermal noise thermometer as claimed in claim 1, including a first circuit for amplifying the thermal noise signal produced in the resistor and a second circuit for amplifying the noise signal produced in said resistor when connected to the shot noise, and means for interrelating the output signals of said first and second circuit.
Claim 8
Dependent Claim
18 words
A thermal noise thermometer as claimed in claim 1, wherein the shot noise source comprises a diode tube.
Claim 9
Dependent Claim
18 words
A thermal noise thermometer as claimed in claim 1, wherein the shot noise source comprises a photoelectric tube.
Claim 10
Dependent Claim
17 words
A thermal noise thermometer as claimed in claim 1, wherein the shot noise source comprises a photo-transistor.
Claim 11
Dependent Claim
23 words
A thermal noise thermometer as claimed in claim 1, wherein the reverse current of a diode is utilized as a shot noise source.
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) | 1981-07-10 | 1982-01-09 | 1982-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-10 | 1986-01-09 | 1986-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-10 | 1990-01-09 | 1990-07-11 | $7700.00 | Window Closed / Lapsed |