Sensor element having temperature measuring means
First Claim
1. A pressure sensor comprising:
- a pressure sensor housing assembly of substantially ceramic material, and including;
a substantially rigid housing part, an at least partly movable diaphragm attached to the housing, and a cavity formed between the substantially rigid housing part and the at least partly movable diaphragm, the substantially rigid housing part comprising a base plate and a shielding plate that is thinner than the base plate, the shielding plate having a surface which forms a wall in the cavity, at least one temperature sensor located between the base plate and the shielding plate and positioned so as to not to interfere with pressure sensing by electrodes in the cavity.
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Accused Products
Abstract
A pressure sensor of substantially ceramic material comprises a rigid housing having a thick base plate, an interior shielding plate, and a movable diaphragm. A cavity providing a reference pressure is formed between the shielding plate and the diaphragm and on the opposite walls thereof are electrodes, which form a capacitor, the capacity of which is sensed. A temperature sensor comprises thermistors positioned inside the housing, between the base plate and the shielding plate, with the reference resistors on the surface of the base plate facing outwards. The shielding plate is thin, so that the thermistors are located near the diaphragm and are sensitive to the temperature thereof. Therefore the temperature sensor element has minimum influence on the electric properties of the pressure sensor and in particular on the mechanical properties of the diaphragm.
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Citations
20 Claims
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1. A pressure sensor comprising:
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a pressure sensor housing assembly of substantially ceramic material, and including;
a substantially rigid housing part, an at least partly movable diaphragm attached to the housing, and a cavity formed between the substantially rigid housing part and the at least partly movable diaphragm, the substantially rigid housing part comprising a base plate and a shielding plate that is thinner than the base plate, the shielding plate having a surface which forms a wall in the cavity, at least one temperature sensor located between the base plate and the shielding plate and positioned so as to not to interfere with pressure sensing by electrodes in the cavity. - View Dependent Claims (4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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2. A pressure sensor comprising:
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a pressure sensor housing assembly of substantially ceramic material, and including;
a substantially rigid housing part, an at least partly movable diaphragm attached to the housing, and a cavity formed between the substantially rigid house part and the at least partly movable diaphragm, the cavity containing pressure sensing electrodes, the substantially rigid housing part comprising a ceramic plate, at least one temperature sensor positioned in the interior of the substantially rigid housing part, separated from the cavity only by the ceramic plate, the ceramic plate being a thin plate having a thickness substantially equal to or larger than the thickness of the at least partly movable diaphragm and at most equal to twice the thickness of the at least partly movable diaphragm. - View Dependent Claims (3)
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17. A pressure sensor, including a temperature sensor, comprising:
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a non-deformable housing comprising a base plate and a shielding plate that is thinner than the base plate;
a diaphragm attached to the housing, the diaphragm including at least a portion movable with the pressure to be sensed;
a cavity formed between the diaphragm and a first surface of the shielding plate;
opposing electrodes formed on the diaphragm and the first surface forming a capacitor for sensing pressure; and
a temperature sensor including first resistive elements positioned between the base plate and a second surface of the shielding plate and second resistive elements positioned on an outward surface of the base plate. - View Dependent Claims (18, 19, 20)
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Specification