Inductance type differential pressure transducer

Abstract

The invention discloses an inductance type differential pressure transducer which comprises a sensor outer shell, a detecting circuit and a sensor body, wherein the detecting circuit is installed inside the outer shell, and the sensor body is formed by two butt joint shell bodies. Installation grooves and air inlet channels communicated with the installation grooves are symmetrically arranged on butt joint faces of the two shell bodies. A group of coil magnetic core assemblies are fixedly connected in each installation groove, the lead-out end of each coil magnetic core assembly is electrically connected with the detecting circuit, an elastic metal membrane is paced between the butt joint faces of the two shell bodies, and sealing rings for sealing and isolating the installation grooves and the air inlet channels are symmetrically placed between two side faces of the elastic metal membrane and the butt joint faces of the two shell bodies. After the coil magnetic core assemblies are powered on, a closed magnetic return path is formed through the elastic metal membrane, and an air gap exists between the magnetic return path and the elastic metal membrane. The inductance type differential pressure transducer is high in sensibility, small in size and measuring range, high-voltage-resisting and suitable for being applied on high-precision airtight detectors which are small in measuring range, high in precision and high-voltage-resisting.

Description

technical field [0001] The invention relates to the technical field of pressure detection, in particular to an inductive differential pressure sensor. Background technique [0002] At present, the sensor composed of iron core and coil that converts the change of linear or angular displacement into the change of coil inductance is also called inductive displacement sensor. The number of turns of the coil and the magnetic permeability of the material of this sensor are constant, and the change of its inductance is caused by the change of the magnetic flux of the coil magnetic circuit caused by the displacement input. When the coil is connected to the measurement circuit and the excitation power is turned on, a voltage or current output proportional to the displacement input can be obtained. The characteristics of inductive sensors are: no movable contacts, high reliability, long life; high resolution; high sensitivity; high linearity, good repeatability, etc. Inductive senso...

AI Technical Summary

Problems solved by technology

When excited by a constant current source, the output voltage of the coil is related to the displacement of the iron core under pressure, so as to calculate the magnitude and direction of the pressure value. The spiral tube pressure inductive sensor has the advantages of simple assembly and manufacturing and a wide measurement range. characteristics, but its sensitivity is low, not suitable for precision measurement; variable air gap inductance sensor, relatively high sensitivity, which consists of three parts of the coil, iron core and armature, there is an air gap between the iron core and the armature, the thickness of the air gap is δ, the moving part of the sensor is connected with the armature, when the armature moves, the thickness of the air gap δ changes, causing the reluctance in the magnetic circuit to change, thus causing the inductance value of the inductance coil to change, so as long as the inductance can be measured change, the size and direction of the displacement generated by the armature compression can be determined

At present, the common variable air gap inductive pressure sensor for measuring air pressure is composed of bellows, iron core, armature and coil. The armature is connected with the upper end of the bellows. Under the action of air pressure P, a displacement proportional to the size of air pressure P is produced, so the armature also moves, so that the air gap changes, and the current flowing through the coil also changes accordingly. The above-mentioned variable air gap type inductance pressure The sensor has high sensitivity, but the sensitivity and nonlinearity decrease with the increase of the air gap, which is not suitable for measuring high-pressure gas. At the same time, because of the relatively large measuring range, the maximum error of the measurement will increase by hundreds or even thousands. times, and the sensor body is not suitable for high-precision air-tight detection equipment with high measurement accuracy and high pressure resistance due to the relatively large volume of the diaphragm box

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