US3672221A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature sensor
Assignee: Monsanto Co
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Filing: 1969-12-19
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Granted: 1972-06-27
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Expires: 1989-12-19
Abstract
Abstract The disclosure herein relates to a method for monitoring the temperature of a material transparent to a given part of the electromagnetic spectrum or of a body in good thermal contact with the material. The preferred method referenced herein utilizes laser radiation to measure variations in the index of refraction of a material with temperature variations. Alternative embodiments refer to variations in the transmission coefficient and reflection coefficient with variation in temperature.
Inventors
- 👤 Raoul B Weil
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:32
CPC Classifications
G; G01; G01J; G01J5/00; G01J5/58; G01J5/02; G01J5/08; G01J5/0803; G01J5/0805; G01J5/0831; G01J5/0896; G01J5/59
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
95 words
Temperature sensing systems comprising in combination: a. at least one body of single-crystal, semi-insulating gallium arsenide transparent to a given part of the electromagnetic spectrum and whose length and index of refraction change with a change in temperature; b. means for irradiating said body with electromagnetic energy at frequencies in the range in which said body is transparent; c. means for detecting and measuring the intensity of that part of said energy not absorbed by said body; and d. means for indicating the intensity output signal from said detecting and measuring means in temperature values.
Claim 2
Dependent Claim
95 words
Temperature sensing systems comprising in combination: a. at least one body of single-crystal, semi-insulating gallium arsenide transparent to a given part of the electromagnetic spectrum and whose length and index of refraction change with a change in temperature; b. means for irradiating said body with electromagnetic energy at frequencies in the range in which said body is transparent; c. means for detecting and measuring the intensity of that part of said energy not absorbed by said body; and d. means for indicating the intensity output signal from said detecting and measuring means in temperature values.
Claim 3
Dependent Claim
30 words
Temperature sensing systems according to claim 1 wherein said body of material is in good thermal contact with a second body the temperature variation of which is to be monitored.
Claim 4
Dependent Claim
80 words
Temperature sensing systems according to claim 1 wherein the sensitivity of said body to temperature variations is determinable in accordance with variations of parameters on the right-hand side of the equation: wherein Delta t pi equals the change required to produce a change from maximum to minimum output energy; lambda o is the wavelength of input energy; L is the length of said body, gamma is the expansion coefficient and delta is the temperature coefficient of the index of refraction.
Claim 5
Dependent Claim
25 words
Temperature sensing systems according to claim 3 wherein a plurality of bodies of material transparent to a given part of the electromagnetic spectrum are used.
Claim 6
Dependent Claim
42 words
Temperature sensing systems according to claim 4 wherein at least one of said bodies is a material different from other of said bodies and the sensitivity of each of said bodies controllable by varying any of the said parameters in the equation.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |