A manufacturing method of a capacitive pressure sensor includes attaching a first electrode and a second electrode onto a first surface of a flexible substrate, attaching a signal processing unit to the flexible substrate, forming a dielectric layer over the first electrode or the second electrode, and folding the flexible substrate so that the first electrode and the second electrode face each other with the dielectric layer being disposed therebetween.

In an embodiment a pressure sensor device includes a substrate body, a pressure sensor having a membrane and a cap body having at least one opening, wherein the pressure sensor is arranged between the substrate body and the cap body in a vertical direction which is perpendicular to a main plane of extension of the substrate body, and wherein the mass of the substrate body amounts to at least 80% of the mass of the cap body and at most 120% of the mass of the cap body.

In an embodiment a pressure sensor device includes a substrate body, a pressure sensor having a membrane and a cap body having at least one opening, wherein the pressure sensor is arranged between the substrate body and the cap body in a vertical direction which is perpendicular to a main plane of extension of the substrate body, and wherein the mass of the substrate body amounts to at least 80% of the mass of the cap body and at most 120% of the mass of the cap body.

Pressure sensors having ring-tensioned membranes are disclosed. A tensioning ring is bonded to a membrane in a manner that results in the tensioning ring applying a tensile force to the membrane, flattening the membrane and reducing or eliminating defects that may have occurred during production. The membrane is bonded to the sensor housing at a point outside the tensioning ring, preventing the process of bonding the membrane to the housing from introducing defects into the tensioned portion of the membrane. A dielectric may be introduced into the gap between the membrane and the counter electrode in a capacitive pressure sensor, resulting in an improved dynamic range.

A resonant pressure sensor includes a first substrate and a resonator. The first substrate includes a diaphragm and a projection disposed on the diaphragm. The resonator is disposed in the first substrate, a part of the resonator being included in the projection, and the resonator being disposed between a top of the projection and an intermediate level of the first substrate. The first substrate is an SOI substrate in which a silicon dioxide layer is inserted between a silicon substrate and a superficial silicon layer. The intermediate level of the first substrate is disposed in the silicon substrate, and the resonator is disposed in the projection included in the superficial silicon layer.

A resonant pressure sensor includes a first substrate and a resonator. The first substrate includes a diaphragm and a projection disposed on the diaphragm. The resonator is disposed in the first substrate, a part of the resonator being included in the projection, and the resonator being disposed between a top of the projection and an intermediate level of the first substrate. The first substrate is an SOI substrate in which a silicon dioxide layer is inserted between a silicon substrate and a superficial silicon layer. The intermediate level of the first substrate is disposed in the silicon substrate, and the resonator is disposed in the projection included in the superficial silicon layer.

Differential density system and method. A differential pressure transmitter measures a pressure difference between first and second pressure sensing locations. A reference vessel in fluid communication with the first pressure sensing location contains a reference fluid and a sample vessel in fluid communication with the second pressure sensing location contains a sample fluid. The reference fluid is in a first column above the first pressure sensing location and the sample fluid is in a second column above the second pressure sensing location. The second column is of substantially equal height as the first column. A value of total dissolved solids (TDS) in the sample fluid is determined based on the pressure difference.

A hermetic terminal (110) includes a barrier wall (12) to be joined to a housing (11), a body (15) that is to be connected to a signal ground and is fixed to the barrier wall (12) via a first insulator (13), and a signal line (16) passing through the body (15) and fixed to the body (15) via a second insulator (14). When the barrier wall (12) is joined to the housing (11), a space (28) is formed between an inner wall of the housing (11) and a surface (31) of the body (15) intersecting an end face (29) of the body (15) positioned towards the inside of the housing (11).

A cover component 3 is used for a pressure sensor 1 that is fixed to a mounting surface 5S of a body 5 with a flow path F1 formed therein, and that has protrudes protruding from the mounting surface 5S, the cover component comprising a hollow member 3a having an inner peripheral surface facing a side surface of the protruding portion of the pressure sensor 1, and a cover member 3b fixed to the hollow member 3a and covering the protruding portion of the pressure sensor 1.

A cover component 3 is used for a pressure sensor 1 that is fixed to a mounting surface 5S of a body 5 with a flow path F1 formed therein, and that has protrudes protruding from the mounting surface 5S, the cover component comprising a hollow member 3a having an inner peripheral surface facing a side surface of the protruding portion of the pressure sensor 1, and a cover member 3b fixed to the hollow member 3a and covering the protruding portion of the pressure sensor 1.