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:
Jul. 24, 2007
Filed:
Mar. 09, 2004
Applicants:
Karen Birkelund, Koebenhavn Oe, DK;
Christoffer Greisen, Valby, DK;
Pirmin Rombach, Lyngby, DK;
Inventors:
Assignee:
Danfoss A/S, Nordborg, DK;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01L 9/06 (2006.01);
U.S. Cl.
CPC ...
Abstract
This invention relates to absolute pressure sensors with two bonded wafers containing a pressure sensing structure and forming a reference pressure chamber and a buffer chamber. Since the buffer chamber collects molecules, which permeate through a bonding interface between the two wafers, a raise in pressure of the reference chamber can be avoided. The sensor is therefore more resistant to pressure equalisation between the pressure chamber and the pressure of the surroundings, i.e. the sensed pressure and repetitive recalibration of the sensor can be avoided.