The present disclosure provides a pressure measuring instrument which comprises a gauge body, a connecting component and a pushing component, the connecting component comprises a first connecting member and a positioning sleeve which are connected with each other to form a corotating relationship, and the first connecting member comprises a first external thread section and a second external thread section connected to each other, and the first external thread section is used for a pressure-measuring hole threaded with a pressure vessel, the second external thread section protrudes from the pressure-measuring hole, the positioning sleeve is rotatably screwed to the second external thread section, and the positioning sleeve is configured to provide a force to the pressure vessel, and the pushing component is configured to pass through the connecting component and be pushed by a fluid in the pressure-measuring hole to push against a pressurize unit of the gauge body.

A device for detecting a sudden pressure variation in a fluid, including a housing open at one of its ends, a wall closing the housing to create a chamber, the wall being configured such that, when the external pressure outside the chamber is substantially stable or varies slowly, the internal pressure of the chamber is close to the external pressure, and the wall having mechanical characteristics such that it breaks when subjected to a predetermined difference between the external pressure and the internal pressure.

If the bridge circuit fails due to damage of the diaphragm, the damage is detected at an early stage. A pressure sensor comprises: a substrate provided with a diaphragm; a bridge circuit having four resistor devices provided at the diaphragm, the bridge circuit being applied with high-voltage-side voltage and low-voltage-side voltage, and having two output terminals; a detecting unit for detecting a first output at a first output terminal and a second output at a second output terminal, each output terminal being of the bridge circuit; and a failure detecting unit for detecting failure of the bridge circuit based on a detection result at the detecting unit.

A pressure switch includes a diaphragm sensing element disposed within a chamber to sealingly separate switching components from a passage. The diaphragm sensing element includes a convolution section that controls movement of a deflection section between neutral and pressurized positions. The pressure switch includes a reverse stop for limiting travel of the deflection section when exposed to negative pressure. A stationary seal element may be disposed at the reverse stop to further limit exposure of the convolution section of the diaphragm sensing element to negative pressure.

A pressure sensor for an evaporated fuel leak detector is used for checking airtightness in a fuel tank and a canister. The pressure sensor includes a sensor unit, a case, and a sealing resin. The sensor unit has a pressure receiving portion, a plurality of conduction terminals, and a mold resin portion. The case has a fluid flow path and a housing recess. A buffer recess having an outer shape larger than the outer shape of a pressure receiving surface is formed at a pressure receiving side L1 of the bottom of the housing recess. Further, a protruding cylinder portion protruding into the buffer recess toward a back side L2 is formed at an outer edge of an opening end portion of the fluid flow path on the back side L2.

The disclosed technology is a pressure transducer with a bleed valve built into the body of the transducer for purging liquid systems. The transducer assembly includes a body, a bleed valve port defined in the body and configured to accept a bleed valve, an interface port attached to the body, an adapter attached to a portion of the interface port, a header attached to the adapter and the body, a pressure transducer mounted to the header, and an internal cavity in communication with the interface port, the pressure transducer, and the bleed valve port. The bleed valve port is configured to vent a gas from the internal cavity. A bleed valve disposed in the bleed valve port is configured to controllably vent a gas from the internal cavity.

The present invention aims to provide a pressure sensor capable of improving waterproofness and airtightness by using a sealing adhesive without the use of an atmosphere-side O-ring or packing and improving workability by filling the sealing adhesive in one direction. In the pressure sensor, a protective cover is formed by any combination of a joint, a lower cover, a pressure detection unit, and a case portion. The protective cover includes a side wall forming an outer periphery and a bottom on the pressure chamber side of the side wall. An opening on a side of the protective cover opposite to the bottom is filled with the sealing adhesive to maintain waterproofness and airtightness of a signal transmission unit.

A metallic base member includes a holding section and a first flange. A sensor chip on which sensor element is arranged is provided on the holding section. An insulating adjusting member is provided on the holding section around the sensor chip and a circumference thereof is positioned between a circumference of the holding section and a circumference of the first flange. A metallic housing includes an opening section and a second flange, an inner surface of the opening section is brought into contact with the circumference of the adjusting member, and the second flange is joined to the first flange.

The present application provides a semiconductor pressure sensor having high manufacturing stability and high accuracy. A second silicon substrate is bonded across an oxide film to one main face of a first silicon substrate, in which a recessed portion that becomes a reference pressure chamber and an alignment mark are formed, whereby the first silicon substrate and the second silicon substrate are joined in a state wherein the recessed portion and the alignment mark are covered by the second silicon substrate. The alignment mark is detected using an infrared sensor, positioning is carried out using the alignment mark, and a gauge resistor, which is a pressure-sensitive element portion, is formed in a diaphragm formed in the second silicon substrate positioned above the recessed portion.

A differential pressure transducer assembly having internal sub-components welded together to improve reliability and ease assembly. A method is provided that includes welding a front adapter to a frontside of a header and welding a back adapter to a backside of the header to create a first sub-assembly. The method includes welding the first sub-assembly to a front attachment port to create a second sub-assembly. The method further includes welding a cap to a backside of the back adapter.