Miniature dynamic osmotic water pressure sensor

Abstract

The invention discloses a minitype dynamic infiltration water pressure sensor which comprises a shell, a cup-shaped base, a stainless steel rear cover, a water permeable stone layer and a signal modulation amplification module. A step surface is arranged on the inner wall of the cup-shaped base, and the water permeable stone layer is mounted on the step surface of the cup-shaped base. The cup-shaped base is embedded into a front cavity and is mounted on the step circular ring surface of the shell. The stainless steel rear cover is mounted at the end, placed on a rear cavity, of the shell, and a silicon nitride thin film covers the inner surface of the cup-shaped base. A pressure sensitive assembly is arranged on the surface, opposite to the water permeable stone layer, of the cup-shaped base, a first leading wire is connected between the pressure sensitive assembly and one end of the signal modulation amplification module in a bridging mode, and a signal cable is embedded into a through hole of the stainless steel rear cover and is connected to the other end of the signal modulation amplification module through a second leading wire. By means of the minitype dynamic infiltration water pressure sensor, the dynamic frequency response and the measurement accuracy of the pressure sensor are improved, the measuring range is greatly increased, sensing precision and sensitivity are also improved, and the degree of linearity of signals of the pressure sensor is improved.

Description

technical field [0001] The invention relates to a pressure sensor, in particular to a miniature dynamic osmotic water pressure sensor. Background technique [0002] At present, the mainstream of measuring water pressure sensors is silicon piezoresistive sensors. The main principle is to use the piezoresistive effect of silicon, adopt MEMS technology and integrated circuit technology to set a certain crystal orientation on a silicon chip, and use oxidation, diffusion or ion implantation to a certain position. Doping, photolithography and other processes are used to make strain-sensitive Wheatstone bridges. Its working range is 1KPa~100Mpa. The silicon piezoresistive sensor is a silicon microchip structure, which cannot directly contact the corrosive mud and seepage water in the soil, that is, it cannot be used as a direct sensing surface. It must be packaged in a stainless steel shell and use a stainless steel diaphragm as the sensing surface. , The interior of the stainles...

AI Technical Summary

Problems solved by technology

The silicon piezoresistive sensor is a silicon microchip structure, which cannot directly contact the corrosive mud and seepage water in the soil, that is, it cannot be used as a direct sensing surface. It must be packaged in a stainless steel shell and use a stainless steel diaphragm as the sensing surface. , the inside of the stainless steel shell is filled with silicone oil as the medium for transmitting pressure, so the high-frequency dynamic frequency response signal is not easy to obtain during use

Due to the elastic force of the stainless steel diaphragm between the permeated water and the pressure sensitive component, it affects the measurement accuracy of the permeated water pressure sensor

In addition, the seepage water in the soil contains a small amount of mud, and it is easy to block and corrode the sensing surface of the stainless steel diaphragm after long-term use, so that the measurement accuracy of the sensor is affected, and the sensor is more likely to be damaged, making the measurement impossible

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