A double-membrane capacitive pressure sensor comprising a glass substrate, wherein a shallow groove is formed in the center of the glass substrate; a shallow groove through-hole is formed in the center of the shallow groove, and the shallow groove through-hole extends from the bottom surface of the shallow groove to the bottom surface of the glass substrate; a capacitor C1 capable of measuring the low-pressure difference and a capacitor C2 capable of measuring the high-pressure difference are arranged above the shallow groove; the capacitor C1 capable of measuring the low-pressure difference comprises a bottom electrode plate and a thin pressure sensitive membrane, and the capacitor C2 capable of measuring the high-pressure difference comprises a thick pressure sensitive membrane and a top electrode plate;

A diaphragm seal assembly, which includes a measuring instrument, a pressure being transmitted from a process side to be monitored, via an arrangement of two diaphragms having an evacuated intermediate space disposed therebetween, to the measuring instrument, reliably separated from the process side, the fatigue strength of the diaphragm seal assembly under extreme application conditions being improved.

A pressure sensing package includes a sensor chamber and an annular chamber extending about the sensor chamber. A primary diaphragm divides the sensor chamber into a first part receiving a first pressure and a second part including a differential pressure sensor approximately centered with respect to a sensor axis and a first transmission fluid. The first transmission fluid transmits the first pressure to a first differential pressure sensor face. A secondary diaphragm divides the annular chamber into a first part receiving a second pressure and a second part including a second transmission fluid. The second pressure is transmitted to a second pressure sensor face via the secondary diaphragm and the second transmission fluid. The primary and secondary diaphragms are positioned with respect to one another along the sensor axis direction such that pressures other than the first and second pressures acting on the pressure sensor sum to approximately zero.

A corrosion protection element is described, with which in simple and cost effective manner a reliable corrosion protection of field devices can be provided, which field devices comprise at least one component of stainless steel in contact with an environment of the field device. Corrosion protection elements of the invention are distinguished by features including that they are embodied as sacrificial anodes comprising iron or rustable steel and have a form, which is embodied in such a manner that they can be applied to the component of the field device in such a manner that the sacrificial anode is in electrically conducting contact with the component.

An apparatus and associated method, for controlling signal passage, includes a first passageway for a first fluid, a second passageway for a second fluid, and an interposed chamber. A first, movable diaphragm at a first chamber junction and a second, movable diaphragm at a second chamber junction, with a third fluid bound there between and interposed between the first and second passageways. A device varies a volume of the third fluid bound between the diaphragms and thus moves the diaphragms. A movable member and a reservoir of the device are configured such that the movable member is sufficiently movable to increase the volume of the reservoir to remove a sufficient portion of the third fluid bound between the first and second diaphragms from the chamber to cause the first and second diaphragms to be pressed against the first and second walls, respectively.

An apparatus includes a sensor body, a sensor configured to measure differential pressure, and first and second pressure inputs in or on the sensor body. The pressure inputs are configured to provide multiple input pressures to the sensor. Each pressure input includes a barrier diaphragm configured to move in response to pressure and an overload diaphragm configured to limit movement of the barrier diaphragm. The overload diaphragm is also configured to exert a preload force against the sensor body. The overload diaphragm of each pressure input may include multiple convolutions. Bases of the convolutions may be configured to provide the preload force, and tops of the convolutions may be separated from the sensor body by gaps. Tops of the convolutions that are non-adjacent may be configured to provide the preload force, and tops of the convolutions between the non-adjacent convolutions may be separated from the sensor body by gaps.

A differential pressure sensor module includes a base having a pair of process fluid pressure inlets and defining a sensor chamber having a sensor chamber inlet. A differential pressure sensor is disposed within the sensor chamber and has an inlet configured to receive a first pressure and provide a signal indicative of a difference between the first pressure and a sensor chamber pressure external to the differential pressure sensor within the sensor chamber. A pair of isolation diaphragms are provided in substantially the same plane, with each isolation diaphragm sealing a respective process fluid pressure inlet. A first fluid passageway is operably coupled to one of the isolation diaphragms and the inlet of the differential pressure sensor. A second fluid passageway is operably coupled to the other of the isolation diaphragms and to the sensor chamber inlet. An overpressure protection feature is operably coupled to the sensor chamber, the first fluid passageway and the second fluid passageway.

A pressure sensor includes a MEMS pressure transducer with a pressure sensing diaphragm and sensor elements, an isolator diaphragm spaced apart from the pressure sensing diaphragm, and a ceramic header body. The ceramic header body has an electrical conductor and transducer aperture with the MEMS pressure transducer supported therein. The isolator diaphragm is coupled to the to the MEMS pressure transducer by a fluid and is sealably fixed to the ceramic body. The ceramic header body bounds the fluid and the electrical conductor electrically connects the MEMS pressure transducer with the external environment. Differential pressure sensors and methods of making pressure sensors are also described.

An overpressure protection system and methods of using the same are provided. The overpressure protection system can include at least two limiting diaphragms in fluid communication with corresponding overpressure diaphragms. Each limiting diaphragm can be configured to transmit pressure exerted by different fluid environments to their corresponding overpressure diaphragm. Each overpressure diaphragm can include a pre-tensioned diaphragm seal configured to allow transmission of pressures to a differential pressure sensing element, allowing measurement of a differential pressure between the different fluid environments. When pressure transmitted to an overpressure diaphragm reaches a pre-defined limit, the pre-tensioned diaphragm can inhibit transmission of further pressure increases to the differential pressure sensing element. The overpressure protection system can employ a relatively small volume of transmission fluid T for pressure transmission, reducing the size of the overpressure protection system and increasing its responsiveness.

An infusion arrangement for administering a medical fluid includes a pump apparatus with an elastomeric membrane which forms a pump volume. The elastomeric membrane is elastically extended in a fill state, filled at least partially with medical fluid, of the pump volume and produces a delivery pressure on the pump volume. An infusion line is connected to the pump volume and provided with a patient access for fluid-conducting connection. A main fluid channel transfers medical fluid from the pump volume to the patient access. A monitoring device is connected to the infusion line and configured for monitoring the pump apparatus. The monitoring device has a differential pressure-measuring element connected to the main fluid channel and designed such that differential pressure formed along a channel portion of the main fluid channel can be detected by the differential pressure-measuring element and a delivery rate of the medical fluid can be indicated.