The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 11, 1993
Filed:
Sep. 11, 1991
Donald L Bond, Sunnyvale, CA (US);
Intelsat, Washington, DC (US);
Abstract
A liquid detector for thin-walled tanks Operating in a zero gravity environment (e.g., outer space). The liquid detector includes a small heater, such as a 1-watt patch heater, and two thermistors positioned on either side of the heater and diametrically opposed to each other. The heater and two thermistors are located on the outside of a propellant tank of, for example, a satellite. One of the thermistors is positioned directly over a region where a propellant management device retains liquid. The other thermistor is spaced apart from the region, while the heater is proximate to the region. In operation, the heater is activated for a short period of time and the change in temperature at each of the two thermistors is observed. The temperature of a thermistor located over a spot having liquid propellant in contact with the tank wall will increase less than the temperature of the thermistor located at a spot where no liquid propellant is present. Thus, by monitoring the temperatures of the thermistors, it is possible to determine if liquid is present and based on the volumetric capacity of the PMD, how much liquid propellant remains in the tank.