Patent ID: 6591683
Filing Date: 2003-07-15
Classification: G01L

Abstract:
A pressure sensor comprising:a diaphragm structure having at least one diaphragm, the diaphragm having first and second surfaces, the first surface of the diaphragm receiving pressure; a first thermal detection unit having a heating unit and arranged opposed to a central section of the second surface of the diaphragm, the first thermal detection unit detecting amount of displacement of the diaphragm caused by a pressure change, based on thermal detection; a first constant-current source which supplies a constant-current to the first thermal detection unit; a second thermal detection unit having a heating unit, wherein the second thermal detection unit is positioned near and opposite a periphery of the second surface of the diaphragm, the second thermal detection unit detecting amount of displacement of the diaphragm caused by a pressure change, based on thermal detection; a second constant-current source which supplies a constant-current to the second thermal detection unit; and a differential amplifier which receives the displacements detected by the first thermal detection unit and the second thermal detection unit.