A self-reinforcing cylindrical double liquid cavity structure high temperature and ultra high pressure sensor

Abstract

A self-reinforcing cylindrical double liquid chamber structure high temperature resistant ultra-high pressure sensor, including a base, a bracket sleeve connected to the base, the bracket sleeve is provided with a bottom filling liquid hole, and the pressure-bearing cylinder is placed in the bracket sleeve , the pressure hole is aligned with the through hole of the base, the sintering seat is connected to the bracket sleeve, the lower step hole of the sintering seat is opened with a sintering hole, the lower step hole is connected to the upper step hole through the liquid through hole, and the side wall of the upper step hole There is an upper liquid filling hole, the sintering column is fixed in the sintering hole, the top cover is connected to the sintering seat, the sensitive element is attached to the step surface of the lower step hole, and the Wheatstone bridge on the sensitive element is connected to the external circuit through the sintering column , the cavity surrounded by the pressure cylinder, the base, the bracket sleeve, the lower step hole and the sensitive element constitutes the lower liquid chamber, and the cavity surrounded by the top cover, the upper step hole, the liquid through hole and the sensitive element constitutes the upper liquid chamber , The lower and upper liquid chambers are filled with compressible liquid, and the double liquid chamber structure forms a high temperature compensation structure to improve the measurement error.

Description

technical field [0001] The invention relates to a pressure sensor, in particular to a high-temperature resistant ultra-high pressure sensor with a self-reinforcing cylindrical double liquid cavity structure. Background technique [0002] The research and development of high temperature and ultra-high pressure sensors has always been the focus of the sensor technology field. Ultra-high pressure sensors are generally designed and manufactured based on capacitance, strain, piezoelectric and piezoresistive effects. The output signal of capacitive sensor is small, the linearity error is large, and a special conditioning circuit is required; the output of strain sensor is also too small, the sensitivity is low, and creep will occur at high temperature; the piezoelectric sensor is mostly used for dynamic pressure measurement. Although quasi-static pressure can be measured through signal processing, it still cannot be used to measure static signals and is sensitive to the measureme...

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Problems solved by technology

However, this type of sensor also has certain shortcomings: 1) The sensitive element is packaged on the metal elastic element through a variety of processes, and the difference in thermal expansion coefficient between the sensitive element, the metal elastic element and the packaging material will generate package residual stress. 2) If the sensitive element is based on the resistance effect of metal, such as a sputtered film or a pressure sensor using a high-temperature foil metal strain gauge, due to the small resistivity of the metal, the resistivity Very low, the sensitivity of the sensor is very small (only a few mV / V), so the signal-to-noise ratio is poor, and the requirements for the subsequent signal processing circuit are relatively high; 3) In the combined structure of elastic elements and sensitive elements, such as pressure-bearing mechanisms, force transmission Mechanisms and other mechanical components, due to their processing errors, assembly errors and other reasons, there will be many unstable factors: For example, in a purely mechanical transmission structure, it is difficult to package the supporting parts and sensitive and pressure-bearing components, and there are system errors caused by processing and assembly Non-systematic errors caused by the characteristics of the packaging material itself; another example is that in the mechanical silicone oil transfer structure, the silicone oil itself is a material with a large temperature and volume change ratio, and there will be temperature stress when used in a wide temperature range, which will make the temperature of the sensor Poor applicability, silicone oil itself has a bulk modulus, and in actual use, system errors will also be introduced due to the existence of the bulk modulus

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