Pressure and differential pressure transmitter

Abstract

The invention relates to the technical field of a sensor and discloses a pressure and differential pressure transmitter, which comprises a base and a positive pressure isolation diaphragm. A spike pulse filter device is arranged on the end surface of the base and located at the inner side of the positive pressure isolation diaphragm. The spike pulse filter device comprises a buffer slot, a seal piston, a buffer spring, a positioning pull rod and a pressure bearing member. Under the action of the compressed elastic force of the buffer spring, the positioning pull rod pulls and locates the sealpiston in the buffer slot. By arranging the spike pulse filter device in a high-pressure chamber of the base, and setting the compressed initial state of the buffer spring to a displacement limit obtained when the positive pressure isolation diaphragm reaches a nominal pressure value, when the system is under the action of the fluid spike or pulse, the pressure exceeding the threshold value preferentially acts on the pressure bearing member through the positive pressure isolation diaphragm to drive the seal piston to compress the buffer spring, and then, the pressure displacement exceeding thethreshold can be buffered by the silicon oil entering the buffer slot, thereby effectively protecting a central pressure sensing diaphragm and related capacitors from the spike pulse.

Description

Technical field [0001] The invention relates to the technical field of sensors, in particular to a pressure differential transmitter. Background technique [0002] Transmitter is any sensor that can output standard signals. It works based on the principle of negative feedback. It is mainly composed of a measuring part, an amplifier and a feedback part. It is a commonly used detection device in process control technology. It can be used according to its pressure-signal conversion method. Divided into: resistance strain gauge pressure transmitter, diffused silicon pressure transmitter, ceramic pressure transmitter, etc. Among them, the pressure transmitter that displays the pressure detection value by the capacitance change is also called a differential pressure transmitter. [0003] Such as figure 1 As shown, the central pressure-sensitive diaphragm 2 is a measuring diaphragm, also called a movable electrode, which forms two capacitive plates with the arc electrodes 6 on both sides...

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Problems solved by technology

[0005] In view of the deficiencies in the use of the existing differential pressure transmitters proposed in the background technology, the present invention provides a pressure differential pressure transmitter, which has the advantages of fluid spike protection function, and solves the problems raised in the above background technology. The problem

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