US4812050A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for calibrating a heat flux gauge
Assignee: Massachusetts Institute of Technology
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Filing: 1987-10-19
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Granted: 1989-03-14
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Expires: 2007-10-19
Abstract
Abstract Double-sided, high-frequency response heat flux gauge for use on metal tune blading consists of a metal film (1500A) resistance thermometer sputtered on both sides of a thin (25 μm) polyimide sheet. The temperature difference across the polyimide is a direct measure of the heat flux at low frequencies, while a quasi-one-dimensional analysis is used to infer the high-frequency heat flux from the upper surface history. A new method of calibrating the heat flux gauge utilizes light source applied to a plurality of fluids covering the surface of the gauge, measuring the temporal output of the gauge and utilizing derived calibration formula.
Inventors
- 👤 Alan H. Epstein
- 👤 Gerald R. Guenette
- 👤 Robert J. G. Norton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:50
CPC Classifications
G; G01; G01K; G01K17/00; G01K17/06; G01K17/08; G01K17/20
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
139 words
A method for providing heat flux gauge measurements for use in calibrating said heat flux gauge comprising the steps of: insuring that the surface of said, heat flux gauge has an emissivity greater than 0.1 over the wavelength band of a light source to be used in calibration; covering the surface of said heat flux gauge with a first fluid of known thermal properties; applying a light source of known modulation to an area encompassing said heat flux gauge; measuring a temporal electrical output of a sensor of said gauge; covering the surface of said heat flux gauge with a second fluid that replaces said first fluid, said second fluid being of known thermal properties; applying said light source to an area encompassing said heat flux gauge; and measuring the temporal electrical output of said sensor of said gauge.
Claim 2
Independent Claim
139 words
A method for providing heat flux gauge measurements for use in calibrating said heat flux gauge comprising the steps of: insuring that the surface of said, heat flux gauge has an emissivity greater than 0.1 over the wavelength band of a light source to be used in calibration; covering the surface of said heat flux gauge with a first fluid of known thermal properties; applying a light source of known modulation to an area encompassing said heat flux gauge; measuring a temporal electrical output of a sensor of said gauge; covering the surface of said heat flux gauge with a second fluid that replaces said first fluid, said second fluid being of known thermal properties; applying said light source to an area encompassing said heat flux gauge; and measuring the temporal electrical output of said sensor of said gauge.
Claim 3
Dependent Claim
39 words
A method for providing heat flux gauge measurements according to claim 1 wherein the resistivity of said sensor does not change more than 1 percent due to covering the surface of said heat flux gauge with said first fluid.
Claim 4
Dependent Claim
39 words
A method for providing heat flux gauge measurements according to claim 1 wherein the resistivity of said sensor does not change more than 1 percent due to covering the surface of said heat flux gauge with said second fluid.
Claim 5
Dependent Claim
74 words
A method for providing a heat flux gauge measurements according to claim 1 wherein the step of insuring that the surface of said heat flux gauge has an emissivity greater than 0.1 over the wavelength band of a light source to be used in calibration includes the step of blackening said heat flux gauge to obtain an emissivity greater than 0.1 over the wavelength band of a light source to be used in calibration.
Claim 6
Dependent Claim
19 words
A method for providing heat flux gauge measurements according to claim 1 wherein said fluids are air and dibutylphalate.
Claim 7
Dependent Claim
32 words
A method for providing heat flux gauge measurements according to claim 2 wherein the resistivity of said sensor does not change more than 1 percent due to blackening said heat flux gauge.
Claim 8
Dependent Claim
36 words
A method for providing heat flux gauge measurements according to claim 2 wherein said first fluid, said second fluid and the blackening on said heat flux gauge are substantially chemically inert to said heat flux gauge.
Claim 9
Independent Claim
179 words
A method for calibrating a heat flux gauge comprising the steps of: insuring that the surface of the heat flux gauge has an emissivity greater than 0.1 over the wavelength band of a light source to be used in the calibration; covering the surface of said sensor with a first fluid of known thermal properties; applying a light source of known modulation to an area encompassing said gauge; measuring a temporal electrical output of a sensor of said gauge; covering the surface of said heat flux gauge with a second fluid that replaces said first fluid, said second fluid being of known thermal properties; applying said light source to an area encompassing said heat-flux gauge; measuring the temporal electrical output of said sensor of said gauge; and applying the calibration formula ##EQU36## wherein M I and M II are the the slopes of the linear region of sensor electrical output vs time when immersed in the respective first and second fluids, s referring to the second fluid, F referring to the first fluid, ρ=density, k=thermal conductivity and c=specific heat.
Claim 10
Independent Claim
179 words
A method for calibrating a heat flux gauge comprising the steps of: insuring that the surface of the heat flux gauge has an emissivity greater than 0.1 over the wavelength band of a light source to be used in the calibration; covering the surface of said sensor with a first fluid of known thermal properties; applying a light source of known modulation to an area encompassing said gauge; measuring a temporal electrical output of a sensor of said gauge; covering the surface of said heat flux gauge with a second fluid that replaces said first fluid, said second fluid being of known thermal properties; applying said light source to an area encompassing said heat-flux gauge; measuring the temporal electrical output of said sensor of said gauge; and applying the calibration formula ##EQU36## wherein M I and M II are the the slopes of the linear region of sensor electrical output vs time when immersed in the respective first and second fluids, s referring to the second fluid, F referring to the first fluid, ρ=density, k=thermal conductivity and c=specific heat.
Claim 11
Dependent Claim
74 words
A method for calibrating a heat flux gauge measurements according to claim 8 wherein the step of insuring that the surface of said heat flux gauge has an emissivity greater than 0.1 over the wavelength band of a light source to be used in calibration includes the step of blackening said heat flux gauge to obtain an emissivity greater than 0.1 over the wavelength band of a light source to be used in calibration.
Claim 12
Dependent Claim
31 words
A method for calibrating a heat flux gauge according to claim 9 wherein resistivity of said sensor does not change more than 1 percent due to blackening said heat flux gauge.
Claim 13
Dependent Claim
36 words
A method for calibrating a heat flux gauge according to claim 9 wherein said first fluid, said second fluid and the blackening on said heat flux gauge are substantially chemically inert to said heat flux gauge.
Claim 14
Dependent Claim
19 words
A method for calibrating a heat flux gauge according to claim 8 wherein said fluids are air and dibutylphthalate.
Claim 15
Dependent Claim
39 words
A method for calibrating a heat flux gauge according to claim 8 wherein the resistivity of said sensor does not change more than 1 percent due to covering the surface of said heat flux gauge with said first fluid.
Claim 16
Dependent Claim
39 words
A method for calibrating a heat flux gauge according to claim 8 wherein the resistivity of said sensor does not change more than 1 percent due to covering the surface of said heat flux gauge with said second fluid.
Claim 17
Independent Claim
198 words
A method for calibrating a heat flux gauge comprising the steps of: insuring that the surface of the heat flux gauge has an emissivity greater than 0.1 over the wavelength band of a light source to be used in the calibration; covering the surface of said sensor with a first fluid of known thermal properties; applying a light source of known modulation to an area encompassing said gauge; measuring a temporal electrical output of a sensor of said gauge; covering the surface of said heat flux gauge with a second fluid that replaces said first fluid, said second fluid being of known thermal properties; applying said light source to an area encompassing said heat flux gauge; measuring the temporal electrical output of said sensor of said gauge; and applying the calibration formula ##EQU37## wherein M I and M II are the slopes of the linear region of sensor electrical output vs. time when immersed in the respective first and second fluids, F referring to the first fluid, ρ=density, k=thermal conductivity of gauge substrate, c=specific heat, d=distance across gauge substrate and (T u -T l ) ss =steady-state temperature difference between the upper and lower surfaces of the gauge.
Claim 18
Independent Claim
198 words
A method for calibrating a heat flux gauge comprising the steps of: insuring that the surface of the heat flux gauge has an emissivity greater than 0.1 over the wavelength band of a light source to be used in the calibration; covering the surface of said sensor with a first fluid of known thermal properties; applying a light source of known modulation to an area encompassing said gauge; measuring a temporal electrical output of a sensor of said gauge; covering the surface of said heat flux gauge with a second fluid that replaces said first fluid, said second fluid being of known thermal properties; applying said light source to an area encompassing said heat flux gauge; measuring the temporal electrical output of said sensor of said gauge; and applying the calibration formula ##EQU37## wherein M I and M II are the slopes of the linear region of sensor electrical output vs. time when immersed in the respective first and second fluids, F referring to the first fluid, ρ=density, k=thermal conductivity of gauge substrate, c=specific heat, d=distance across gauge substrate and (T u -T l ) ss =steady-state temperature difference between the upper and lower surfaces of the gauge.
Claim 19
Dependent Claim
72 words
A method for calibrating a heat flux gauge measurements according to claim 15 wherein the step of insuring that the surface of said heat flux gauge had an emissivity greater than 0.1 over the wavelength band of light source to be used in calibration includes a step of blackening said heat flux gauge to obtain an emissivity greater than 0.1 over the wavelength band of light source to be used in calibration.
Claim 20
Dependent Claim
32 words
A method for calibrating a heat flux gauge according to claim 16 wherein the resistivity of said sensor does not change more than 1 percent due to blackening said heat flux gauge.
Claim 21
Dependent Claim
36 words
A method for calibrating a heat flux gauge according to claim 17 wherein said first fluid, said second fluid and the blackening on said heat flux gauge are substantially chemically inert to said heat flux gauge.
Claim 22
Dependent Claim
39 words
A method for calibrating a heat flux gauge according to claim 15 wherein the resistivity of said sensor does not change more than 1 percent due to covering the surface of said heat flux gauge with said first fluid.
Claim 23
Dependent Claim
39 words
A method for calibrating a heat flux gauge according to claim 15 wherein the resistivity of said sensor does not change more than 1 percent due to covering the surface of said heat flux gauge with said second fluid.
Claim 24
Dependent Claim
19 words
A method for calibrating a heat flux gauge according to claim 15 wherein said fluids are air and dibutylphthalate.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-03-13 | 1992-09-12 | 1993-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-13 | 1996-09-12 | 1997-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-13 | 2000-09-12 | 2001-03-14 | $7700.00 | Window Closed / Lapsed |