A pressure detecting device is mounted in a measurement target and instrument includes a strain inducer to which pressure of a pressure medium is applied and which generates strain in accordance with the pressure and a strain detecting element that is bonded onto a surface opposite to a pressure receiving surface of the strain inducer, in which the strain detecting element includes one or multiple central strain resistant bridges which are arranged at a central portion of the strain detecting element in a bonded surface direction, and one or multiple outer peripheral strain resistant bridges which are arranged at an outer periphery, and in which, for example, deformation of the strain detecting element caused by an external force when being screw-fixed to the measurement target instrument is obtained through the multiple strain resistant bridges. An error of detection pressure caused by the deformation in a pressure value detected through the central strain resistant bridge is corrected.

The invention relates to a method for determining a pressure measurement signal in a capacitive pressure measurement cell which comprises a main body and a measurement membrane that is arranged on the front of said main body. Electrodes are arranged on said main body and measurement membrane and form a measurement capacitance in a region of the measurement membrane which has a high degree of pressure sensitivity, and form a reference capacitance in a region of the measurement membrane which has a lower degree of pressure sensitivity, said measurement capacitance and reference capacitance being determined independently of one another, the pressure measurement signal being determined in a first measurement range from the measurement capacitance and the reference capacitance, in accordance with the first evaluation, and said pressure measurement signal being determined in a second measurement range from the reference capacitance in accordance with a second evaluation.

A microelectromechanical system (MEMS) strain gauge pressure sensor includes a top wafer stack having a top surface and a first cavity that is configured to receive a first fluid at a first pressure, a backing wafer having a bottom surface opposite the top surface of the top wafer stack; a diaphragm wafer positioned between the top wafer stack and the backing wafer and having a second cavity that is configured to receive a second fluid at a second pressure, and a pedestal connected laterally to the top wafer stack, the backing wafer, and the diaphragm wafer. The diaphragm wafer includes a diaphragm extending between the first cavity and the second cavity, and a resistor positioned on the diaphragm. The MEMS strain gauge pressure sensor has a central axis such that the MEMS strain gauge pressure sensor has mechanical symmetries about the central axis.

A pressure sensor made of semiconductor material, the sensor comprising a box defining a housing under a secondary vacuum, at least one resonator received in the housing and suspended by flexible beams from at least one elastically deformable diaphragm closing the housing that also contains means for exciting the resonator in order to set the resonator into vibration and detector means for detecting a vibration frequency of the resonator. The detector means comprise at least a first suspended piezoresistive strain gauge having one end secured to one of the beams and one end secured to the diaphragm. The resonator and the first strain gauge are arranged to form zones of doping that are substantially identical in kind and in concentration.

A differential pressure sensor comprises a cavity having a base including a base electrode and a membrane suspended above the base which includes a membrane electrode, wherein the first membrane is sealed with the cavity defined beneath the first membrane. A first pressure input port is coupled to the space above the sealed first membrane. A capacitive read out system is used to measure the capacitance between the base electrode and membrane electrode. An interconnecting channel is between the cavity and a second pressure input port, so that the sensor is responsive to the differential pressure applied to opposite sides of the membrane by the two input ports.

A differential pressure sensor for determining a differential pressure value, comprising: a differential pressure measuring transducer having a measuring membrane; a membrane seal having a membrane seal body including a pressure chamber filled with a transmission fluid in which a filling body having a recess is arranged, wherein the differential pressure measuring transducer arranged in the recess, wherein a first pressure is applied to the differential pressure measuring transducer on a first measuring membrane side and a second pressure is applied to a second measuring membrane side such that deformation of the measuring membrane represents a differential pressure value between the first pressure and the second pressure, wherein a piezoelectric layer for determining an absolute pressure value of the first pressure is provided inside the pressure chamber.

A differential pressure measuring device (10, 50) comprising a housing (18) having two pressure areas (20, 22) which are sealed relative to each other and are separated from each other by a membrane (12, 54). The membrane (12, 54) comprises a pressure plate (14) surrounded by an elastic circumferential area (16) allowing axial movement of the pressure plate (14). An indicator element (24, 56) is permanently connected to the pressure plate (14) and whose position can be evaluated in a non-contact manner by a sensor (34, 58). At least one pair of springs (28, 52) is provided, with one spring (30, 32) each of said pair of springs being located in an allocated pressure area (20, 22). Each spring (30, 32) of said pair of springs (28, 52) exerts an opposing spring force on the pressure plate (14).

A sensing system that provides an isolation diaphragm through which pressure is transmitted from a process fluid to a fill fluid contained within the sensing system's body is provided. In the system, fill fluid transfers pressure to semiconductor sensors that provide signals for both the differential pressure and the static pressure, thereby allowing for signal conditioning of the differential output to compensate for the effects of static pressure. The system's body provides a cavity for fill fluid behind each of the isolation diaphragms. At least one flat plate actuation diaphragm allows controlled movement of oil as the differential pressure of the isolation diaphragm increases. Fluid volumes are managed for thermal effects, passive thermal volume change; compensation is accomplish by offsetting the large coefficient of thermal expansion (CTE) of fill fluid by providing at least one insert whose coefficient of thermal expansion is smaller than the CTE of the system body.

This invention relates to a device for measuring differential pressure comprising a first pressure measurement means (11) measuring a first pressure value (P1) and a second pressure measurement means (12) measuring a second pressure value (P2), the second pressure measurement means (12) being configured to read the pressure (P1) measured by the first pressure measurement means (11), calculate the pressure difference between the pressure (P1) measured by the first pressure measurement means (11) and the pressure (P2) measured by the second pressure measurement means (12), and transmit the differential pressure value in the form of a single signal. The first pressure measurement means (11) is of the analogue or digital type and the second pressure measurement means (12) is of the digital type and the value of the differential pressure transmitted is in the form of a single digital signal.

A load lock pressure gauge comprises a housing configured to be coupled to a load lock vacuum chamber. The housing supports an absolute vacuum pressure sensor that provides instantaneous high vacuum pressure signal over a range of high vacuum pressures and a differential diaphragm pressure sensor that provides an instantaneous differential pressure signal between load lock pressure and ambient pressure. The housing further supports an absolute ambient pressure sensor. A low vacuum absolute pressure is computed from the instantaneous differential pressure signal and the instantaneous ambient pressure signal. A controller in the housing is able to recalibrate the differential diaphragm pressure sensor based on measured voltages of the sensor and a measured ambient pressure during normal operation of the pressure gauge with routine cycling of pressure in the load lock.