US5092170A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Measurement of mass of fluid in a container
Assignee: Matra Marconi Space UK Ltd
•
Filing: 1990-05-08
•
Granted: 1992-03-03
•
Expires: 2010-05-08
Abstract
Abstract The mass of fluid remaining in a container 10 is determined by switching on a series of heating elements 14 and sensing the temperature of the container and contents over a period of time using sensor 16, thereby to deduce the thermal time constant. The thermal time constant is used to determine the mass of the remaining fluid contents from a look-up table or other means. In an alternative arrangement, the thermal response on cooling may be used in a similar manner.
Inventors
- 👤 Ian A. Honstvet
- 👤 Mark S. Kendrew
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:30
CPC Classifications
B; B64; B64G; B64G1/00; B64G1/22; B64G1/40; B64G1/402; G; G01; G01F; G01F23/00; G01F23/22
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
74 words
A method of determining the mass of fluid remaining in a container, which method comprises the steps of: heating the container, detecting and measuring the temperature of the container and any fluid contained therein, deducing a temperature vs. time curve for the container and any fluid therein, devising from said curve the thermal time constant of said curve, and using said thermal time constant to determine the mass of fluid remaining in said container.
Claim 2
Independent Claim
74 words
A method of determining the mass of fluid remaining in a container, which method comprises the steps of: heating the container, detecting and measuring the temperature of the container and any fluid contained therein, deducing a temperature vs. time curve for the container and any fluid therein, devising from said curve the thermal time constant of said curve, and using said thermal time constant to determine the mass of fluid remaining in said container.
Claim 3
Dependent Claim
50 words
A method according to claim 1, wherein said time constant (τ) is deduced substantially in accordance with the following formula: ##EQU6## where T 1 , T 2 , T 3 are temperatures of the container and any fluid therein at times t 1 , t 2 , t 3 respectively.
Claim 4
Dependent Claim
53 words
A method according to claim 1, wherein said time constant (τ) is deduced substantially in accordance with the following formula: ##EQU7## where T∞ is the steady state temperature attained by the container and any fluid therein and T(a), T(b) are the temperatures of the container and any fluid therein at times t(a), t(b).
Claim 5
Dependent Claim
58 words
A method according to claim 1, wherein said time constant (τ) is deduced substantially in accordance with the following formula: ##EQU8## where To, T∞ are the initial and steady state temperatures respectively of the container and any fluid therein and T(b) is the temperature of the container and any fluid therein at time t after start of heating.
Claim 6
Dependent Claim
19 words
A method according to claim 1, wherein the container is mounted on a spacecraft and contains a propellant fluid.
Claim 7
Dependent Claim
30 words
A method according to claim 1, wherein the thermal time constant is derived from values on said temperature vs. time curve after a preset period following start of said heating.
Claim 8
Dependent Claim
19 words
A method according to claim 1, wherein said container is heated by at least one heating element associated therewith.
Claim 9
Dependent Claim
82 words
Apparatus for determining the mass of fluid remaining in a container, said apparatus comprising means for heating said container, temperature sensor means for sensing the temperature of the container and any fluid contained therein, and processor means responsive to the output of said temperature sensor means for monitoring a temperature vs. time curve for the container and any fluid therein to deduce the thermal time constant of said curve and to determine the mass of fluid remaining using said thermal time constant.
Claim 10
Dependent Claim
82 words
Apparatus for determining the mass of fluid remaining in a container, said apparatus comprising means for heating said container, temperature sensor means for sensing the temperature of the container and any fluid contained therein, and processor means responsive to the output of said temperature sensor means for monitoring a temperature vs. time curve for the container and any fluid therein to deduce the thermal time constant of said curve and to determine the mass of fluid remaining using said thermal time constant.
Claim 11
Dependent Claim
8 words
A spacecraft including apparatus according to claim 8.
Claim 12
Dependent Claim
123 words
A spacecraft having a plurality of containers containing propellant fluid under pressure and each having associated therewith apparatus for determining the mass remaining therein, said apparatus comprising means for heating said container, temperature sensor means for sensing the temperature of the container and any fluid contained therein, and processor means responsive to the output of said temperature sensor means for monitoring a temperature vs. time curve for the container and any fluid therein to deduce the thermal time constant of said curve and to determine the mass of fluid remaining using said thermal time constant, wherein propellant fluid may be transferred from one container to another on the basis of the values obtained for the masses of propellant fluid remaining in the containers.
Claim 13
Dependent Claim
123 words
A spacecraft having a plurality of containers containing propellant fluid under pressure and each having associated therewith apparatus for determining the mass remaining therein, said apparatus comprising means for heating said container, temperature sensor means for sensing the temperature of the container and any fluid contained therein, and processor means responsive to the output of said temperature sensor means for monitoring a temperature vs. time curve for the container and any fluid therein to deduce the thermal time constant of said curve and to determine the mass of fluid remaining using said thermal time constant, wherein propellant fluid may be transferred from one container to another on the basis of the values obtained for the masses of propellant fluid remaining in the containers.
Claim 14
Independent Claim
76 words
A method of determining the mass of fluid remaining in a container, which method comprises the steps of: allowing the container to cool, detecting and measuring the temperature of the container and any fluid contained therein, deducing a temperature vs. time curve for the container and any fluid therein, devising from said curve the thermal time constant of said curve, and using said thermal time constant to determine the mass of fluid remaining in said container.
Claim 15
Independent Claim
76 words
A method of determining the mass of fluid remaining in a container, which method comprises the steps of: allowing the container to cool, detecting and measuring the temperature of the container and any fluid contained therein, deducing a temperature vs. time curve for the container and any fluid therein, devising from said curve the thermal time constant of said curve, and using said thermal time constant to determine the mass of fluid remaining in said container.
References Cited (Backward Citations)
US3922658A
Cited
US3955416A
Cited
US4729245A
Cited
US4825383A
Cited
JPS62294911A
Cited
US4805454A
Cited
US4898030A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-03-03 | 1995-09-02 | 1996-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-03 | 1999-09-02 | 2000-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-03 | 2003-09-02 | 2004-03-03 | $7700.00 | Window Closed / Lapsed |